Managing HP Serviceguard for Linux, Tenth Edition, September 2012

the new up criteria does not cause the resource status to evaluate to 'down' (i.e.,
the current_value of the resource still satisfies the new up_criteria).
• Modification of resource type from a simple resource to an extended resource is
allowed only if the generic_resource_evaluation_type is
during_package_start in all the running packages that currently use the
resource.
About Package Dependencies
A package can have dependencies on other packages, meaning the package will not
start on a node unless the packages it depends on are running on that node.
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” (page 211).
As of A.11.19, Serviceguard adds two new capabilities: you can specify broadly where
the package depended on must be running, and you can specify that it must be down.
These capabilities are discussed later in this section under “Extended Dependencies”
(page 136). You should read the next section, “Simple Dependencies” (page 130), first.
Simple Dependencies
A simple dependency occurs when one package requires another to be running on the
same node. You define these conditions by means of the parameters
dependency_condition and dependency_location, using the literal values UP
and same_node, respectively. (For detailed configuration information, see the package
parameter definitions starting with “dependency_name” (page 210). For a discussion
of complex dependencies, see
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, use the Rules
for Simple Dependencies and Guidelines for Simple Dependencies (page 135) that follow.
Rules for Simple Dependencies
Assume that we want to make pkg1 depend on pkg2.
130 Planning and Documenting an HA Cluster