Monitoring and alerting with Prometheus and PromQL. Free practice questions sampled from our full 120-question bank, with detailed explanations for every option.
Format
multi-choice
Duration
90 min
Pass mark
75%
Study time
2–8 wks
Mocks here
2
What the PCA exam tests
The Prometheus Certified Associate exam is structured around 5 weighted domains. Each domain link below opens a focused practice page with sample questions from that area.
One representative question per domain, drawn from the 120-question pool. Click "Reveal answer" to see the correct option plus explanations for every distractor.
Observability Concepts
Q1. The Four Golden Signals from the Google SRE book are which four metrics?
Reveal answer and explanations
ACPU, memory, disk, and network
Incorrect. These are system resources, not the SRE Golden Signals.
BAvailability, latency, throughput, and cost
Incorrect. Although related to reliability, these are not the canonical Golden Signals.
CRate, errors, duration, and utilization
Incorrect. This mixes RED and USE; it is not the Golden Signals definition.
DLatency, traffic, errors, and saturation
Correct. The Four Golden Signals are latency, traffic, errors, and saturation — the baseline signals to monitor for any user-facing service.
Prometheus Fundamentals
Q2. What is the primary purpose of Prometheus `remote_write`?
Reveal answer and explanations
ATo allow an operator to write ad-hoc samples via HTTP POST to the local TSDB for debugging purposes
Incorrect. `remote_write` is not an interactive ingestion API; the Pushgateway is used for short-lived job ingestion.
BTo replicate TSDB blocks to a standby Prometheus for disaster recovery at block granularity continuously
Incorrect. It is not block-level replication; it forwards samples on ingest.
CStream samples to long-term storage like Thanos or Cortex
Correct. `remote_write` forwards incoming samples over HTTP to a compatible backend, enabling long-term storage, global querying, or downsampling outside the local TSDB.
DTo expose a writable `/metrics` endpoint so other services can push values over HTTP continuously in bulk
Incorrect. `/metrics` is an exposition endpoint; remote_write is an egress mechanism.
PromQL
Q3. What is the key difference between `avg(metric)` and `avg_over_time(metric[5m])`?
Reveal answer and explanations
A`avg()` across series at an instant; `avg_over_time()` across time
Correct. `avg()` is an aggregation operator that averages values of different series at the evaluation instant; `avg_over_time()` averages samples of each series across the specified range.
BThey are aliases for the same computation under different grammar rules for convenience in the language itself
Incorrect. They compute different things along different dimensions.
C`avg()` works only on counters while `avg_over_time()` works only on gauges in strict mode during evaluation
Incorrect. Metric type is not what distinguishes them.
D`avg()` uses SI decimal units and `avg_over_time()` uses binary IEC units internally for the numeric output
Incorrect. Units are unrelated to the distinction.
Instrumentation and Exporters
Q4. Which of the following labels is the most dangerous from a cardinality perspective and should generally be avoided in instrumentation?
Reveal answer and explanations
A`method` with values like `GET`, `POST`, `PUT`, `DELETE`
Incorrect. HTTP methods are low-cardinality (a handful of values); safe to label on.
B`status_code` using HTTP status classes like `2xx`, `4xx`, `5xx`
Incorrect. Status classes are bounded and low-cardinality.
C`environment` like `prod`, `staging`, `dev`
Incorrect. Environment values are typically a small fixed set.
D`user_id` per-request
Correct. Unbounded identifiers like `user_id`, `request_id`, or full URLs explode series count, inflate memory, and can destabilize Prometheus — instrument with bounded labels only.
Alerting & Dashboarding
Q5. How do multiple Alertmanager replicas coordinate to deliver notifications exactly once in a highly-available deployment?
Reveal answer and explanations
AA Raft-based leader election picks one instance to send all notifications on behalf of the cluster at any time during peer rotation
Incorrect. Alertmanager HA is not leader-based; Raft is used by other systems.
BThey share a Redis cluster that stores dispatch state, acquiring distributed locks per alert fingerprint before sending notifications
Incorrect. No external datastore like Redis is required or used.
CGossip mesh: peers share state, single delivery
Correct. Alertmanager peers connect via `--cluster.peer` and share state over a gossip protocol, so even though all peers receive alerts from Prometheus, only one sends the notification to each receiver.
DHA is not supported; you must run a single replica and fail over manually via a DNS change during any outage of the active node itself
Incorrect. HA via clustered gossip is explicitly supported and recommended for production.
Roughly 2–8 weeks of focused study, but it depends heavily on what you already know. Engineers with hands-on production Kubernetes (or Cilium / Argo / OTel / etc. for project-specific certs) can compress this to a week or two of mocks; people coming in cold should expect the upper end. The exam is multi-choice and recall-heavy — practice exams matter more than reading documentation cover to cover. Aim for 85%+ on full timed mocks before booking the real exam.
Why this practice library
This library was built by a Platform Engineer chasing Golden Kubestronaut who got frustrated by the lack of decent practice material for the associate-tier CNCF exams. Question banks track curriculum updates from CNCF and Linux Foundation.