A metric instance is a record in the metric_instance table. A record holds one instance
of a metric.
Metric instance records get created and updated in one of two ways: 1) If the metric is a
duration, the system automatically populates the metric instance table with duration values. 2)
If the metric is calculated from a script, the script itself must populate the metric_instance
table.
Figure 1. Metric plugin
Some of the notable fields in the metric_instance table are:
- Metric definition: the metric definition for which this metric instance was
gathered.
- Value: For a "Field value duration" metric this is the value of the table
field for which duration is calculated. For example, for the "Assigned to Duration" metric, the
Value is the name of the person assigned to the incident. For other metrics, the value can be
any value calculated by the metric.
- ID: Identifies the specific record for which the metric is gathered. For
example, the specific incident.
- Duration: Time duration for a Field value duration metric.
