Metrics with Micrometer in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Micrometer in Spring Boot?

Micrometer is a library that helps collect and publish application metrics in Spring Boot. It acts like a bridge to many monitoring systems, making it easy to track app performance.

beginner

How do you create a custom counter metric using Micrometer?

You use the MeterRegistry to create a Counter. For example: <br>Counter counter = meterRegistry.counter("my_counter");<br>counter.increment(); This counts how many times an event happens.

intermediate

What is the role of MeterRegistry in Micrometer?

MeterRegistry is the main interface to register and manage all metrics like counters, gauges, and timers. It connects your app metrics to monitoring systems.

intermediate

Explain the difference between a Gauge and a Counter in Micrometer.

A Counter only goes up and counts events (like clicks). A Gauge measures a value that can go up or down (like current memory usage).

intermediate

How does Micrometer support multiple monitoring systems?

Micrometer uses 'binders' and 'exporters' to send metrics to many systems like Prometheus, Graphite, or New Relic without changing your code.

Which Micrometer component is used to register and manage metrics?

A MetricManager

B MetricCollector

C MeterRegistry

D MetricPublisher

MeterRegistry is the core interface to register and manage metrics in Micrometer.

What type of metric should you use to count how many times an event happens?

A Histogram

B Gauge

C Timer

D Counter

A Counter only increases and is used to count events.

Which of these metrics can go up and down in value?

A Counter

B Gauge

C Timer

D Summary

A Gauge measures values that can increase or decrease, like current temperature.

How does Micrometer send metrics to different monitoring systems?

A Using binders and exporters

B By rewriting code for each system

C Only supports Prometheus

D Using database triggers

Micrometer uses binders and exporters to support many monitoring systems without code changes.

In Spring Boot, how do you typically get access to MeterRegistry?

A By injecting it as a bean

B By reading from a config file

C By creating a new instance manually

D By calling a static method

MeterRegistry is injected as a bean in Spring Boot for easy use.

Describe how you would add a custom counter metric in a Spring Boot app using Micrometer.

Think about how you get MeterRegistry and how to use it to count events.

Explain the difference between a Gauge and a Counter metric and give an example of when to use each.

Consider if the value changes only up or both ways.