PCA Observability Concepts Practice Question
A developer adds a 'user_id' label to an HTTP request counter. What is the operational risk?
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
✓
High cardinality will consume excessive memory.
Adding a high-cardinality dimension like 'user_id' can explode the number of time series created, crashing the TSDB.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
High cardinality will consume excessive memory.
Why this is correct
Each user_id will create a separate time series.
- ✗
The query speed will increase.
Why it's wrong here
Query speed will decrease as it has more to filter.
- ✗
Prometheus will reject the metric.
Why it's wrong here
Prometheus will accept it until it runs out of memory.
- ✗
The metric will stop recording.
Why it's wrong here
It will record, but at high cost.
About these practice questions
One of 304 original PCA practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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.