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Metrics & Dimensions

Hands-on2 exercises

From OIDs to Metrics

Every metric needs three things: a key, a value (the OID), and a type.

metrics:
  - key: my_device.cpu_usage
    value: oid:1.3.6.1.4.1.9.9.109.1.1.1.1.8
    type: gauge

Metric Types

Type	Behavior	Examples	Key Suffix
`gauge`	Point-in-time value, stored as-is	CPU %, temperature, memory	No `.count`
`count`	Cumulative counter, Dynatrace calculates rate	Bytes, packets, errors	Must end in `.count`

💡 If the value only goes up (until reset) → count. If it fluctuates → gauge.

Metric Key Naming

Prefix with your extension name. The .count suffix rule is enforced by the validator:

# Correct
- key: cisco_aci.cpu_usage          # gauge — no .count
  type: gauge
- key: cisco_aci.if.in.octets.count # count — has .count
  type: count

# Wrong — triggers DED006/DED007 warnings
- key: cisco_aci.if.in.octets       # count missing .count suffix
  type: count

🛠 Try it

Add a CPU metric with the correct type. CPU usage is a point-in-time percentage — is that gauge or count?

extension.yamlYAML

Metric Metadata

Define display names and units in the top-level metrics: section:

metrics:
  - key: my_device.cpu_usage
    metadata:
      displayName: CPU Usage (5 min avg)
      unit: Percent

Available units:

Unit	Use For
`Percent`	CPU, memory, bandwidth utilization
`Byte`	Memory, disk, traffic volumes
`Count`	Packets, errors, sessions
`MilliSecond`	Latency, response time
`Celsius`	Temperature sensors
`MegaBit`	Interface speed
`Unspecified`	Anything else

Dimensions

Dimensions are labels attached to metrics. Three value sources:

dimensions:
  - key: device.address
    value: this:device.address    # from monitoring config
  - key: sys.name
    value: oid:1.3.6.1.2.1.1.5.0 # from SNMP device
  - key: device.type
    value: const:Cisco Switch     # hardcoded constant

💡 oid: = read from device, this: = from monitoring config, const: = hardcoded value.

🛠 Try itExercise 2

Add a const: dimension for device type and an oid: dimension for sysDescr (1.3.6.1.2.1.1.1.0).

extension.yamlYAML

What's Next

In Module 3, you'll organize metrics into groups and feature sets — so users can toggle monitoring sections on/off.

← PreviousSNMP FundamentalsNext →Groups & Feature Sets