Measuring and improving performance

You will recall from earlier chapters that by definition, a resource is a service that is made highly available by the cluster. Every resource is assigned what is called a resource agent, an external shell script that manages the actual resource for the cluster, independently of how those services would be managed by systemd if they were left to its care. Thus, the actual operation of the resource is transparent to the cluster, since it is being managed by the resource agent.

Resource agents are found inside /usr/lib/ocf/resource.d, so feel free to take a look at them to become better acquainted with their structure. In most circumstances, you will not need to modify them, but work on the specific resources' configuration files, as we shall see. You will recall from earlier chapters that adding a cluster resource involved using an argument of the standard:provider:resource_agent form (ocf:heartbeat:mysql, for example).You can also view the complete list...