Prometheus and Metrics

Question 1

What is Grafana?

Answer 1

Grafana is a visualization and analytics software. Grafana allows you to query, visualize, alert on, and explore your metrics, logs, and traces no matter where they are stored. It provides you with tools to turn your time-series database (TSDB) data into insightful graphs and visualizations.

Question 2

What is the default port for Grafana?

Answer 2

Port 3000.

Question 3

What is a Grafana Dashboard?

Answer 3

A collection of panels organized and arranged into one or more rows.

Question 4

What is a Grafana Panel?

Answer 4

A panel is the basic visualization building block in Grafana. Each panel has a query editor specific to the data source selected in the panel. There are many visualization options available to display on the panel.

Question 5

What is Prometheus?

Answer 5

Prometheus is an open-source systems monitoring and alerting toolkit. It collects and stores its metrics as time series data.

Question 6

True or False: Prometheus was originally built at Google.

Answer 6

False. Prometheus was originally built at SoundCloud.

Question 7

What are metrics?

Answer 7

Metrics are numeric measurements. Metrics play an important role in understanding your application. For example, a web server might monitor request times as a metric, allowing the development team to discover why certain requests are slow.

Question 8

What is time-series data?

Answer 8

Metrics information stored with the timestamp at which it was recorded, alongside optional key-value pairs called labels.

Question 9

What is PromQL?

Answer 9

Prometheus Query Language is a functional query language that leverages the multi-dimensionality (many labels) of Prometheus metrics to easily search/display metrics.

Question 10

How does Prometheus collect time-series data?

Answer 10

Prometheus uses a pull model. Prometheus collects metrics from targets by scraping metrics HTTP endpoints.

Question 11

True or False: Prometheus supports pushing time series.

Answer 11

True. Prometheus can be configured to accept metrics via the push model using an intermediary gateway, but the pull model is default. Note that Prometheus will still pull from the Pushgateway.

Question 12

How can Prometheus discover targets?

Answer 12

Targets are discovered via service discovery or static configuration.

Question 13

What is the Alertmanager?

Answer 13

The Alertmanager handles alerts sent by Prometheus (and others). It takes care of deduplicating, grouping, and routing them to the correct receiver. It also takes care of silencing and inhibition of alerts.

Question 14

What is the Spring Boot Actuator?

Answer 14

The Spring Boot Actuator uses HTTP endpoints to expose operational information about any running application. The main benefit of using this library is that we get health and monitoring metrics from production-ready applications.

Question 15

How can we configure the Spring Boot Actuator?

Answer 15

in application.yml:
management:
  endpoints:
    web:
      exposure:
        include: health, metrics, prometheus

Question 16

What is Micrometer?

Answer 16

Micrometer provides a simple facade over the instrumentation clients for the most popular monitoring systems. In essence, micrometer serves as an interface that allows you to choose between different JVM-based monitoring systems under the hood.

Question 17

Why do we record application metrics with Micrometer?

Answer 17

Application metrics recorded by Micrometer are used to observe, alert, and react to the current/recent operational state of your environment.

Question 18

True or False: We can define custom metrics in a Spring Boot application using Micrometer.

Answer 18

True.