Actuator endpoints overview in Spring Boot - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary purpose of Spring Boot Actuator endpoints?

Spring Boot Actuator provides several endpoints. What is their main purpose?

A To serve static web pages for the application frontend.

B To expose operational information about the running application for monitoring and management.

C To handle user authentication and authorization.

D To compile and build the application during runtime.

💡 Hint

Think about what monitoring tools need from a running app.

Actuator endpoints provide details like health, metrics, and environment info to help monitor and manage the app.

❓ component_behavior

intermediate

What output does the /actuator/health endpoint produce by default?

Consider a default Spring Boot app with Actuator enabled. What is the typical JSON output of the /actuator/health endpoint?

A {"state":"running"}

B {"result":"healthy"}

C {"health":"OK"}

D {"status":"UP"}

💡 Hint

Look for the key that indicates overall system status.

The health endpoint returns a JSON with a status key showing the app health, usually "UP" if all is well.

📝 Syntax

advanced

Which configuration enables all Actuator endpoints in Spring Boot 3.x?

Given the following application.properties snippet, which option correctly enables all Actuator endpoints?

Spring Boot

management.endpoints.web.exposure.include=

A management.endpoints.web.exposure.include=*

B management.endpoints.web.exposure.include=health,info,metrics,env

C management.endpoints.web.exposure.include=all

D management.endpoints.web.exposure.include=enabled

💡 Hint

Use the wildcard symbol to include all endpoints.

Setting management.endpoints.web.exposure.include=* exposes all available endpoints.

❓ state_output

advanced

What is the output of /actuator/metrics/jvm.memory.used endpoint?

When you access /actuator/metrics/jvm.memory.used, what kind of data do you expect to see?

A {"name":"jvm.memory.used","measurements":[{"statistic":"VALUE","value":12345678.0}],"availableTags":[]}

B {"memoryUsed":"12345678"}

C {"metric":"memory","used":true}

D {"status":"UP"}

💡 Hint

Look for a JSON structure with name, measurements, and statistics.

The metrics endpoint returns detailed JSON including metric name and measurement values.

🔧 Debug

expert

Why does the /actuator/env endpoint return 404 error by default?

You try to access /actuator/env but get a 404 Not Found error. What is the most likely reason?

A The application does not have the Actuator dependency added.

B The env endpoint is deprecated and removed in Spring Boot 3.x.

C The env endpoint is not exposed by default and must be explicitly enabled in configuration.

D The server port is incorrect in the request URL.

💡 Hint

Check which endpoints are exposed by default and which require explicit enabling.

By default, only a few endpoints like health and info are exposed. Others like env need to be enabled explicitly.