Understanding Serviceguard Package Dependencies, April 2009

All nodes exclusionary (down) dependency example

Pkg1 requires pkg2 to be down in the cluster before it can start and in order to continue running. This

dependency is mutual. Pkg1 needs to define an all nodes “down” dependency on pkg2 and pkg2

needs to define an all nodes “down” dependency on pkg1. Both configuration files must be applied

at the same time. Note that at least one of these packages must be assigned a numerical priority; the

priority of both packages cannot be “no_priority”.

Include the following in the configuration file for pkg1:

Dependency_name pkg2dep

Dependency_condtion pkg2=down

Dependency_location all_nodes

Include the following in the configuration file for pkg2:

Dependency_name pkg1dep

Dependency_condtion pkg1=down

Dependency_location all_nodes

Multiple dependency example

Say you have the following requirement:

• Pkg1 requires pkg2 to be down on the same node before it can start and in order to continue

running. However pkg2 can be up on another node in the cluster. This dependency is mutual. Pkg1

needs to define a “down” dependency on pkg2 and pkg2 needs to define a “down” dependency

on pkg1. Both configuration files must be applied at the same time.

• Pkg1 requires pkg3 to be up on any node in the cluster before it can start and in order to

continue running.

Include the following in the configuration file for pkg1:

Dependency_name pkg2dep

Dependency_condtion pkg2=down

Dependency_location same_node

Dependency_name pkg3dep

Dependency_condtion pkg3=up

Dependency_location any_node

Include the following in the configuration file for pkg2:

Dependency_name pkg1dep

Dependency_condtion pkg1=down

Dependency_location same_node