Writing Monitors for the Event Monitoring Service (December 1999)

74 Chapter3
Creating a Resource Monitor
Defining the Resource Dictionary Hierarchy
• RESOURCE_NAME: resource_name
Required. The RESOURCE_NAME is the key identifier that allows a
resource monitor to be integrated into EMS.
resource_name is a full path name (starting with /). This can be
either a class name or an instance, with nothing to differentiate
between the two.
/ is the class delimiter.
• STATE_TYPE:[A|S|B]
Defaulted. The STATE_TYPE specifies the method used by the monitor
to collect the status of information. The default value is S (STATE).
A—Asynchronous type. This monitor is event driven. It is not polled
by EMS. The monitor reports events to EMS asynchronously. EMS
checks these continuous messages against the user defined
parameters. This monitor type does not store values about resources.
A typical use for this monitor type is for hardware event monitors
which continuously send events. Asynchronous monitors can monitor
all hardware instances individually.
S—State type. Default. This monitor checks the status of the resource
at specific (polling) intervals. This monitor is polled. A monitor that is
part of an MC/ServiceGuard package must use STATE_TYPE S
because MC/ServiceGuard searches for status UP. If
MC/ServiceGuard receives any value other than UP,
MC/ServiceGuard halts the package and attempts to move it to
another node.
B—Both type. The STATE_TYPE must be defined for each resource,
resource class and resource subclass. When a resource class contains
a combination of Asynchronous and State subclasses or resource
instances, the parent resource class must be identified as Both.