on that package; in our example, pkg1 is a successor of pkg2; conversely pkg2 can be referred to as a predecessor of pkg1.)

Dragging Rules for Simple Dependencies

The priority parameter (page 238) gives you a way to influence the startup, failover, and failback behavior of a set of failover packages that have a configured_node failover_policy, when one or more of those packages depend on another or others.

The broad rule is that a higher-priority package can drag a lower-priority package, forcing it to start on, or move to, a node that suits the higher-priority package.

NOTE: This applies only when the packages are automatically started (package switching enabled); cmrunpkg will never force a package to halt.

Keep in mind that you do not have to set priority, even when one or more packages depend on another. The default value, no_priority, may often result in the behavior you want. For example, if pkg1 depends on pkg2, and priority is set to no_priority for both packages, and other parameters such as node_name and auto_run are set as recommended in this section, then pkg1 will normally follow pkg2 to wherever both can run, and this is the common-sense (and may be the most desirable) outcome.

The following examples express the rules as they apply to two failover packages whose failover_policy (page 237) is configured_node. Assume pkg1 depends on pkg2, that node1, node2 and node3 are all specified (not necessarily in that order) under node_name (page 235) in the configuration file for each package, and that failback_policy (page 238) is set to automatic for each package.

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HP Serviceguard manual Dragging Rules for Simple Dependencies