4.1. What is a Cluster Resource?
A resource is a service made highly available by a cluster. The simplest type of resource, a primitive resource, is described in this section. More complex forms, such as groups and clones, are described in later sections.
Every primitive resource has a resource agent. A resource agent is an external program that abstracts the service it provides and present a consistent view to the cluster.
This allows the cluster to be agnostic about the resources it manages. The cluster doesn’t need to understand how the resource works because it relies on the resource agent to do the right thing when given a start, stop or monitor command. For this reason, it is crucial that resource agents are well-tested.
Typically, resource agents come in the form of shell scripts. However, they can be written using any technology (such as C, Python or Perl) that the author is comfortable with.
