The difference between metrics and properties, and when a super metric is the answer.
From Ultra Transcenders 2V0-17.25 by Tony Rough (publishing soon)
Everything VCF Operations shows is built from two kinds of collected data, metrics and properties, plus the super metrics you calculate from them.
| Aspect | Metrics | Properties |
|---|---|---|
| What they describe | Operational or performance values (for example CPU usage) | Configuration and attributes of an object (for example a VM’s disk space or hardware settings) |
| Typical use | Time-series charts on the Metrics tab, trends, capacity, dynamic thresholds | Inventory and configuration context, change detection, filtering and grouping |
| Thresholds | Static thresholds or dynamic thresholds calculated from history | Compared to a value in a property symptom |
| Symptom wait and cancel cycles | Configurable | Cannot be edited for property conditions |
| Alert cancelled manually | Regenerated at the next collection and analysis cycle if the condition persists | Same: regenerated if the condition persists |
In a policy’s Metrics and Properties section you activate, deactivate or inherit each metric, property and super metric for an object type, mark it as a KPI (a violation against a KPI generates an alert) and control whether dynamic thresholds (DT) apply. Dynamic thresholds are calculated from historical and incoming data on a regular schedule (activated by default, under Administration > Global Settings), in addition to fixed thresholds. On the Metrics tab, a yellow diamond marks a dynamic threshold breach.
A super metric is a mathematical formula that contains one or more metrics or properties, used when no single metric tells you what you need.
avg, an object type, a metric, and a depth: depth 1 is one level above the source object, 2 is two levels above, negative depth aggregates parents of a child; depth can never be 0, so aggregating VMs to a datastore cluster needs two super metrics. A where clause can filter on a metric of the same object (for example powered-on VMs) but cannot reference another object.A super metric is only calculated where it is activated in a policy applied to the objects.
Common trap: Creating a super metric and expecting values to appear - it must be assigned to an object type and activated in the policy that applies to those objects.
This note is one section of Ultra Transcenders 2V0-17.25: VMware Cloud Foundation Administrator, an independent study guide that explains every topic the exam covers by technology, with comparison tables, diagrams and the common traps, plus a glossary linked to Broadcom TechDocs.
Publishing soon on Amazon in Kindle and paperback editions.
About the book · 2V0-17.25 terms in the glossary · All 2V0-17.25 study notes
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