PCA Instrumentation And Exporters — 10 Questions

Question 1

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 2

You need to track the number of requests received by your application. Which metric type should you choose?

Accepted Answer

Counter. A counter is a cumulative metric that represents a single monotonically increasing counter whose value can only increase or be reset to zero on restart.

Answer

Summary

Answer

Gauge

Answer

Histogram

Question 3

Which action should be avoided when creating labels for custom metrics?

Accepted Answer

Using high-cardinality labels. Adding high-cardinality data (like user IDs or unique request IDs) to labels causes an explosion in the number of time series, which can crash Prometheus.

Answer

Using static labels

Answer

Adding job labels

Answer

Adding instance labels

Question 4

When implementing a custom exporter, what format must the output follow to be correctly scraped by Prometheus?

Accepted Answer

Prometheus Text Format. Prometheus requires a text-based format where each metric is represented by lines, including name, labels, and values.

Answer

JSON

Answer

XML

Answer

Binary Protobuf

Question 5

You are using the blackbox_exporter to monitor an HTTP endpoint. Which module configuration is required to check the HTTP status code?

Accepted Answer

http_2xx. The http_2xx module is the standard configuration for checking that an endpoint returns a successful HTTP status code.

Answer

dns_query

Answer

tcp_connect

Answer

icmp_ping

Question 6

A developer wants to expose a metric that represents the current memory usage of a process. Which type is most appropriate?

Accepted Answer

Gauge. A Gauge represents a numerical value that can arbitrarily go up and down, such as memory usage or temperature.

Answer

Counter

Answer

Summary

Answer

Histogram

Question 7

You need to monitor the duration of database queries. Which metric type is best for calculating quantiles on the server side?

Accepted Answer

Histogram. Summaries calculate configurable quantiles on the client side, while Histograms require server-side calculations.

Answer

Gauge

Answer

Counter

Answer

Summary

Question 8

You are monitoring a Linux server and need to track CPU usage. Which exporter is the standard choice for exposing hardware and OS metrics?

Accepted Answer

node_exporter. node_exporter is the standard Prometheus exporter for hardware and OS metrics exposed by *NIX kernels.

Answer

mysqld_exporter

Answer

blackbox_exporter

Answer

pushgateway

Question 9

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 10

When running node_exporter, how can you disable specific collectors like 'textfile'?

Accepted Answer

--no-collector.textfile. Collectors can be disabled using the --no-collector.<name> flag.

Answer

collector.textfile=false

Answer

exclude=textfile

Answer

--disable-textfile