PCA Exam Guide: Prometheus Certified Associate Domains (2026)

Overview

What PCA actually certifies

The Prometheus Certified Associate is the CNCF and Linux Foundation credential for engineers who monitor systems with Prometheus. Unlike the CKA or CKAD it is not performance-based: it is an online, proctored, multiple-choice exam lasting 90 minutes, priced at $250 for the exam alone, and the certification is valid for two years. The Linux Foundation does not publish a question count or a pass mark, so treat any number you see for those as hearsay.

What it does publish is the blueprint, and CNCF open-sources the curriculum itself, so the domain list is not something a prep site has to guess at. Five domains, and the weights are the whole study plan: PromQL 28 %, Prometheus Fundamentals 20 %, Observability Concepts 18 %, Alerting & Dashboarding 18 %, Instrumentation and Exporters 16 %.

PCA is one of seven CNCF associate exams, all priced and shaped alike — if you are still deciding between them, which cloud native certification should you take? compares all seven side by side. Gnoseed does not sell, proctor or accredit this exam and has no affiliation with CNCF or the Linux Foundation. What it offers is free spaced-repetition practice on the material the blueprint names — so verify every fact above against the official exam page before you book, because prices and formats move.

Breakdown

The exam at a glance

One exam, five domains, and a study plan that reaches across three decks — for the reason explained below.

PCA

Prometheus Certified Associate

AssociateMultiple choice · online proctored · 90 min · $250Prereq: None

The blueprint is unusually honest about where the difficulty lives. PromQL alone is 28 % — selecting data, rates and derivatives, aggregating over time and over dimensions, binary operators, histograms and timestamp metrics. Prometheus Fundamentals (20 %) covers system architecture, configuration and scraping, the data model and labels, the exposition format, and — notably — understanding Prometheus limitations. Alerting & Dashboarding (18 %) is rules, Alertmanager and the when-what-why of alerting. Instrumentation and Exporters (16 %) is client libraries, exporters and metric naming. The fifth domain is the one people misjudge, and it gets its own section below.

Choose this if…

You already run Prometheus and want the gaps in your mental model found
You want a vendor-neutral observability credential without a hands-on lab exam
You are preparing for CKA-adjacent platform work where monitoring is your slice

Study with Gnoseed

Prometheus & Observability · 79 cards Observability: Grafana, Logs & Traces · 62 cards Site Reliability Engineering · 123 cards

Where the marks are

More than a quarter of the exam is PromQL

If you rank the domains by weight, PromQL is the largest by eight points, and it is also the part that punishes recognition-level knowledge hardest. Knowing that rate() exists is not the same as knowing what it returns when a counter goes from 100 to 400 across a five-minute window, why rate(sum(x)) is not sum(rate(x)), or why a topk(3, …) graph can draw more than three lines.

The curriculum names seven PromQL competencies: selecting data, rates and derivatives, aggregating over time, aggregating over dimensions, binary operators, histograms, and timestamp metrics. Two of those trip people who use PromQL daily. Aggregating over time (avg_over_time and its family) is a different operation from aggregating over dimensions (avg, sum by) — one collapses a range vector per series, the other collapses across series at one instant. And timestamp metrics — a metric whose value is a Unix time — are read with time() - metric, which is obvious only once you have seen it.

A practical rule: if your revision time is limited, spend it in blueprint order. Perfecting Alertmanager routing trees buys 18 % of the paper; being fluent in PromQL buys 28 % and makes the Alerting domain easier as a side effect, because alerting rules are PromQL expressions.

The domain people misjudge

Observability Concepts is barely about Prometheus

The fifth domain is Observability Concepts at 18 %, and its published competencies are: metrics, understanding logs and events, tracing and spans, push versus pull, service discovery, and the basics of SLOs, SLAs and SLIs. Read that list again — tracing, logs and service-level objectives are not Prometheus features. Prometheus stores numeric time series and nothing else; traces live in Tempo or Jaeger, logs in Loki or Elasticsearch, and SLOs are an SRE practice that Prometheus merely happens to be good at measuring.

That is why a candidate who has only ever operated Prometheus can lose most of a domain worth roughly a fifth of the exam. You are expected to know what a span is and how it relates to a trace, why logs answer a question metrics cannot, and how an SLI differs from an SLO and from the contractual SLA sitting behind it — without any of it being a question about a scrape config.

It also explains the study plan on this page. The Prometheus deck covers the four Prometheus-shaped domains and the SLI side of the fifth; the Observability deck covers signals, traces, spans and the OpenTelemetry vocabulary; and the SRE deck covers SLOs, SLAs, error budgets and the when-what-why of alerting. Three decks, because the blueprint genuinely spans three subjects.

Before you book

What the blueprint deliberately leaves out

The published curriculum lists competencies, not depth, and two practical things are simply absent from it. There is no stated question count and no stated pass mark — figures circulating in blog posts are inference, not policy. And there is no stated Prometheus version, which matters more than it sounds: PromQL has kept growing, and a question set written against one minor release can read oddly against another.

Two more things worth knowing. The exam includes a free retake, and it is frequently bundled with the Linux Foundation's own course (LFS241) at a price below buying both separately — so compare the bundle against the standalone exam before paying. And because the certification expires after two years, treat it as a checkpoint rather than a trophy: the material it covers is the material you use, which is exactly the case for spaced repetition rather than a cram week.

FAQ

Common questions

Is the PCA exam hands-on like the CKA? +

No. PCA is an online, proctored, multiple-choice exam lasting 90 minutes. There is no terminal and no cluster to fix, which makes it a knowledge exam rather than a performance-based one — and makes recall-style practice a good fit for it.

What are the PCA exam domains and their weights? +

Five domains: PromQL 28 %, Prometheus Fundamentals 20 %, Observability Concepts 18 %, Alerting & Dashboarding 18 %, and Instrumentation and Exporters 16 %. CNCF open-sources the full curriculum, so the competency bullets under each domain are public too.

How much does PCA cost and how long is it valid? +

The exam alone is $250 and the certification is valid for two years. It is often sold bundled with the Linux Foundation course LFS241 for less than the two bought separately. Check the official page for current pricing before you book.

How many questions are on the PCA exam, and what is the passing score? +

Neither is published by the Linux Foundation. Any specific number you find for the question count or the pass mark is someone's inference rather than official policy, so plan your preparation around the domain weights instead.

Do I need to know Grafana for the PCA exam? +

Dashboarding basics are part of the Alerting & Dashboarding domain, but the curriculum does not name a dashboard product, so the exam tests the idea rather than the tool — what belongs on a dashboard as opposed to in an alert. Knowing Grafana will not hurt, and it is the tool you will meet in practice.

Do I need to know tracing and logging for a Prometheus exam? +

Yes, and it surprises people. The Observability Concepts domain is 18 % of the exam and explicitly lists tracing and spans, logs and events, and the basics of SLOs, SLAs and SLIs — none of which Prometheus itself does. That is why this study plan spans three decks rather than one.

Study the blueprint, not a question dump

Plant your first seed today. The domains are public and the weights tell you where to spend your ten minutes a day — start with PromQL.

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PCA: The Prometheus Certified Associate Exam, Domain by Domain