3.3. Resource Trees - Basics / Definitions
3.3. Resource Trees - Basics / Definitions The following illustrates the structure of a resource tree, with a corresponding list that defines each area. Resource trees are XML representations of resources, their attributes, parent/child and sibling relationships. The root of a resource tree is almost always a special type of resource called a service. Resource tree, resource group, and service are usually used interchangeably on this wiki. From RGManager's perspective, a resource tree is an atomic unit. All components of a resource tree are started on the same cluster node. fs:myfs and ip:10.1.1.2 are siblings fs:myfs is the parent of script:script_child script:script_child is the child of fs:myfs 3.3.1. Parent / Child Relationships, Dependencies, and Start Ordering The rules for parent/child relationships in the resource tree are fairly simple: Parents are started before children Children must all stop (cleanly) before a parent may be stopped From these two, you could say that a child resource is dependent on its parent resource In order for a resource to be considered in good health, all of its dependent children must also be in good health
<service name="foo" ...> <fs name="myfs" ...> <script name="script_child"/> </fs> <ip address="10.1.1.2" .../> </service>