Appendix D. HA Resource Behavior
system-config-cluster, or by editing
etc/cluster/cluster.conf. For descriptions of HA resource parameters, refer to Appendix C, HA Resource Parameters. To understand resource agents in more detail you can view them in
/usr/share/clusterof any cluster node.
/etc/cluster/cluster.conf(in each cluster node). In the cluster configuration file, each resource tree is an XML representation that specifies each resource, its attributes, and its relationship among other resources in the resource tree (parent, child, and sibling relationships).
/etc/cluster/cluster.conf, for illustration purposes only.
D.1. Parent, Child, and Sibling Relationships Among Resources
rgmanager. All resources in a service run on the same node. From the perspective of
rgmanager, a cluster service is one entity that can be started, stopped, or relocated. Within a cluster service, however, the hierarchy of the resources determines the order in which each resource is started and stopped.The hierarchical levels consist of parent, child, and sibling.
fs:myfs(<fs name="myfs" ...>) and
ip:10.1.1.2(<ip address="10.1.1.2 .../>) are siblings.
fs:myfs(<fs name="myfs" ...>) is the parent of
script:script_child(<script name="script_child"/>) is the child of
fs:myfs(<fs name="myfs" ...>).
Example D.1. Resource Hierarchy of Service foo
<service name="foo" ...> <fs name="myfs" ...> <script name="script_child"/> </fs> <ip address="10.1.1.2" .../> </service>
- Parents are started before children.
- Children must all stop cleanly before a parent may be stopped.
- For a resource to be considered in good health, all its children must be in good health.