PCA Practice Test 7 — 10 Questions

Question 1

A team wants to visualize metrics from Prometheus in Grafana. What is the standard way to connect these two services?

Accepted Answer

Add a 'Prometheus' data source in Grafana. Grafana allows users to add Prometheus as a 'Data Source' by providing the URL of the Prometheus server.

Answer

Upload a JSON file to Prometheus

Answer

Configure a Prometheus scrape job for Grafana

Answer

Install the 'Grafana-exporter' in Prometheus

Question 2

Your application has a short-lived batch job that finishes before the Prometheus server can scrape it. What architectural component should be used?

Accepted Answer

Pushgateway. The Pushgateway is designed to allow ephemeral and batch jobs to expose their metrics to Prometheus.

Answer

Prometheus API

Answer

Alertmanager

Answer

node_exporter

Question 3

What is the primary function of the 'blackbox_exporter' in a monitoring architecture?

Accepted Answer

Endpoint probing. It allows monitoring of endpoints from the outside (blackbox perspective) rather than the inside (whitebox instrumentation).

Answer

Database performance

Answer

Log aggregation

Answer

Hardware monitoring

Question 4

You have a histogram metric tracking request durations. You need to calculate the 99th percentile across all instances in a cluster. Why is this difficult with standard Prometheus metrics?

Accepted Answer

Aggregating histograms requires complex math because they track bucket counts, not raw values.. Histograms track counts in predefined buckets. Without knowing the exact distribution of values within those buckets, calculating accurate quantiles across multiple instances or time windows is an approximation.

Answer

Histograms can only be used on a single instance.

Answer

The Prometheus server does not support mathematical operations.

Answer

Histograms are not designed to be aggregated across multiple labels.

Question 5

You need to ensure that an alert remains 'firing' for 5 minutes before the Alertmanager is notified. Which field in the Prometheus alerting rule should you configure?

Accepted Answer

for. The 'for' field in a Prometheus alerting rule specifies the duration for which a condition must be true before the alert transitions from 'pending' to 'firing'.

Answer

pending_duration

Answer

delay

Answer

hold_time

Question 6

Which metric type is most appropriate for tracking the current total number of active user sessions?

Accepted Answer

Gauge. Since the count of active sessions can rise and fall, a gauge is the correct metric type.

Answer

Summary

Answer

Counter

Answer

Histogram

Question 7

What is the default port used by node_exporter?

Accepted Answer

9100. The standard Prometheus convention for node_exporter is port 9100.

Answer

9115

Answer

9090

Answer

8080

Question 8

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 9

What is the primary function of the 'scrape_timeout' configuration?

Accepted Answer

It limits the duration of the HTTP connection.. It defines how long Prometheus waits for a response from the target before considering the scrape a failure.

Answer

It determines how long to keep metrics in memory.

Answer

It sets the interval between scrapes.

Answer

It restricts the size of the metric payload.

Question 10

Your team is defining Service Level Objectives (SLOs) for a web application. Which metric is most indicative of the 'Traffic' golden signal?

Accepted Answer

Number of requests per second. Traffic is a measure of demand on the system, typically represented by request rate per second.

Answer

Database connection pool size

Answer

Total disk I/O wait

Answer

Number of active error logs

Answer

Average CPU utilization percentage