KCNA Cloud Native Observability Practice Question
Which TWO of the following are valid Prometheus metric types? (Select two)
⚠ Common exam trap
KCNA often tests whether candidates confuse Prometheus metric types with StatsD (Set, Timer) or OpenTelemetry (Meter) terminology, so memorizing the exact four Prometheus types is essential.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Counter
Prometheus defines Counter as a core metric type: a cumulative value that only increases (or resets to zero on restart), typically used for counts like total requests or errors, and queried with rate()/increase(). Option E (Gauge) is also correct because Prometheus defines Gauge as a metric type representing a value that can arbitrarily go up and down, such as temperature, memory usage, or current queue depth. The other options are not Prometheus metric types: Set, Timer, and Meter are metric abstractions found in other monitoring libraries/systems (for example, Dropwizard Metrics or Micrometer), not in the Prometheus client data model, whose four types are Counter, Gauge, Histogram, and Summary.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Set
Why it's wrong here
Set is not a Prometheus metric type; the four are counter, gauge, histogram and summary. Set is tempting because it is a real StatsD and Graphite concept, and would be the correct choice in a StatsD question, but Prometheus has no set instrument.
- ✓
Counter
Why this is correct
A Counter is a cumulative Prometheus metric that only increases or resets to zero on restart, suitable for totals such as requests served. PromQL's rate() and increase() functions operate on counters, distinguishing them from gauges, histograms, and summaries.
- ✗
Timer
Why it's wrong here
Timer is not a Prometheus metric type; Prometheus records durations using histogram or summary instead. Timer is tempting because it is a genuine Micrometer and Dropwizard instrument, and would be correct in a Micrometer question, but Prometheus exposes no timer type.
- ✗
Meter
Why it's wrong here
Meter is a Dropwizard and Micrometer instrument, not a Prometheus metric type; Prometheus defines counter, gauge, histogram and summary. It is tempting because Meter is a genuine metrics abstraction elsewhere, and would be the right answer in a Micrometer or Dropwizard question rather than a Prometheus one.
- ✓
Gauge
Why this is correct
A Gauge is a Prometheus metric representing a single numerical value that can arbitrarily increase or decrease, such as temperature or current memory usage. Unlike counters, gauges are sampled directly without rate() conversion, making them one of the four valid metric types.
Go deeper
Related to this question
About these practice questions
Courseiva writes every KCNA question from scratch — 930 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CNCF exam blueprint
This KCNA practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the KCNA exam.