PCA Observability Concepts Practice Question
You need to measure the P99 latency of your service. Which PromQL function do you use on a Histogram?
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
✓
histogram_quantile()
The 'histogram_quantile' function is required to calculate quantiles from bucketed histogram data.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
histogram_quantile()
Why this is correct
This is the correct function for quantiles.
- ✗
avg()
Why it's wrong here
avg() provides the mean, not P99.
- ✗
sum()
Why it's wrong here
sum() aggregates values.
- ✗
rate()
Why it's wrong here
rate() calculates per-second growth.
About these practice questions
This PCA question is part of Courseiva's 304-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam 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 August 2026 · checked against the official CNCF / Linux Foundation exam blueprint
This PCA practice question is part of Courseiva's free CNCF / Linux Foundation 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 PCA exam.