Managing Serviceguard 14th Edition, June 2007

Planning and Documenting an HA Cluster
Package Configuration Planning
Chapter 4172
In Serviceguard A.11.17, package dependencies are supported only for
use with certain applications specified by HP, such as the multi-node and
system multi-node packages that HP supplies for use with Veritas
Cluster File System (CFS) on systems that support it.
As of Serviceguard A.11.18, package dependency is no longer restricted;
you can make a package dependent on any other package or packages
running on the same cluster node, subject to the restrictions spelled out
in Chapter 6, under dependency_condition (see page 287).
Make a package dependent on another package if the first package
cannot (or should not) function without the services provided by the
second. For example, pkg1 might run a real-time web interface to a
database managed by pkg2. In this case it might make sense to make
pkg1 dependent on pkg2.
In considering whether or not to create a dependency between packages,
consider the Rules and Guidelines that follow.
Rules
Assume that we want to make pkg1 depend on pkg2.
NOTE pkg1 can depend on more than one other package, and pkg2 can depend
on another package or packages; we are assuming only two packages in
order to make the rules as clear as possible.
• pkg1 will not start on any node unless pkg2 is running on that node.
• pkg1’s package_type (see page 282) and failover_policy (see
page 285) constrain the type and characteristics of pkg2, as follows:
—If pkg1 is a multi-node package, pkg2 must be a multi-node or
system multi-node package. (Note that system multi-node
packages are not supported for general use.)
—If pkg1 is a failover package and its failover_policy is
min_package_node, pkg2 must be a multi-node or system
multi-node package.
—If pkg1 is a failover package and its failover_policy is
configured_node, pkg2 must be:
— a multi-node or system multi-node package, or