PCA Prometheus Fundamentals Practice Test 2 — 15 Questions

Question 1

Which TWO of the following labels are specifically associated with Histograms?

Accepted Answer

sum. In Prometheus histograms, the exposed time series carry the label `le` ("less than or equal to"), which defines each bucket's upper bound, so option C is correct. Histograms also expose the `_sum` series, which aggregates the sum of all observed values and is identified by the `sum` label suffix, making option B correct. Options A (percentile) and D (quantile) are associated with summaries, not histograms, since summaries expose configurable quantiles directly. Option E (range) is not a standard histogram label; histograms use cumulative `le` buckets rather than a range label.

Answer

percentile

Answer

quantile

Answer

range

Question 2

When configuring Alertmanager to send notifications to Slack, which block defines the routing tree?

Accepted Answer

route. In Alertmanager's configuration, the route block defines the routing tree that determines how alerts are grouped and which receiver they are sent to. It is the top-level entry point (with child routes for matching) that evaluates alert labels against matchers and dispatches notifications accordingly.

Answer

receivers

Answer

inhibit_rules

Answer

global

Question 3

Which file format does Prometheus use for its main configuration?

Accepted Answer

YAML. Prometheus configuration is strictly defined in YAML format.

Answer

XML

Answer

JSON

Answer

TOML

Question 4

In the Prometheus data model, what is a 'sample'?

Accepted Answer

A value and a timestamp. A sample is a value-timestamp pair associated with a specific series.

Answer

The metric name

Answer

A label key-value pair

Answer

An alert rule

Question 5

You are deploying Prometheus in a Kubernetes cluster and need to ensure it discovers pods labeled 'app=frontend'. Which configuration block is required?

Accepted Answer

kubernetes_sd_configs. kubernetes_sd_configs is the standard mechanism to discover pods dynamically.

Answer

dns_sd_configs

Answer

static_configs

Answer

file_sd_configs

Question 6

A batch job runs for only 30 seconds every hour. How should you expose these metrics to Prometheus?

Accepted Answer

Use the Pushgateway. The Pushgateway is designed specifically for short-lived jobs that cannot be scraped directly.

Answer

Use an exporter sidecar

Answer

Increase scrape interval to 1 hour

Answer

Add a scrape_config for the batch job

Question 7

Which component is responsible for receiving alerts from Prometheus and managing notification delivery?

Accepted Answer

Alertmanager. Alertmanager is the dedicated component for deduplicating, grouping, and routing alerts.

Answer

Prometheus Server

Answer

Exporter

Answer

Pushgateway

Question 8

Your Prometheus server is hitting high memory usage due to high cardinality. Which action is most effective at reducing memory pressure?

Accepted Answer

Drop high-cardinality labels using relabel_configs. Reducing label cardinality (e.g., removing unique user IDs) is the primary way to reduce TSDB index size and memory usage.

Answer

Increase scrape_interval

Answer

Use more exporters

Answer

Enable remote write

Question 9

What is the default port that Prometheus listens on?

Accepted Answer

9090. 9090 is the well-known default port for the Prometheus server web interface.

Answer

9100

Answer

9093

Answer

8080

Question 10

You are performing a 'label_replace' operation. What is the correct syntax for a regex capture group?

Accepted Answer

$1. Prometheus uses standard RE2 regex syntax, where capture groups are accessed via $1, $2, etc.

Answer

\1

Answer

{1}

Answer

%1

Question 11

Which TSDB component is responsible for ensuring data durability if the server crashes?

Accepted Answer

WAL (Write-Ahead Log). The Write-Ahead Log (WAL) is a crucial component in Prometheus's TSDB that ensures data durability. Before data is written to the in-memory Head block, it is first appended to the WAL on disk. If the server crashes, the WAL can be replayed to recover any data that was not yet persisted to disk.

Answer

Tombstone file

Answer

Head block

Answer

Index file

Question 12

Which mechanism allows Prometheus to discover targets by reading a list from a file?

Accepted Answer

file_sd_configs. file_sd_configs is designed to read target lists from JSON or YAML files.

Answer

dns_sd_configs

Answer

static_configs

Answer

consul_sd_configs

Question 13

What is the primary language used to query Prometheus data?

Accepted Answer

PromQL. PromQL (Prometheus Query Language) is the functional query language for Prometheus.

Answer

Regex

Answer

GraphQL

Answer

SQL

Question 14

When using the 'scrape_timeout', what happens if the timeout is reached?

Accepted Answer

The scrape is marked as failed. If the timeout is reached, the scrape is aborted, and a 'up{job=...} == 0' metric is recorded.

Answer

It automatically retries once

Answer

The previous value is kept indefinitely

Answer

The scrape continues silently

Question 15

Which component is best suited for long-term storage?

Accepted Answer

Remote write storage. Prometheus is not designed for indefinite storage; external remote write storage is needed for long-term retention.

Answer

The local TSDB

Answer

Pushgateway

Answer

Alertmanager