Actuator endpoints overview in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of Spring Boot Actuator endpoints?

Spring Boot Actuator endpoints provide ready-made HTTP endpoints to monitor and manage your application, such as checking health, metrics, and configuration details.

beginner

Name three common Actuator endpoints and their uses.

/health: Shows application health status.
/metrics: Displays various metrics like memory and CPU usage.
/info: Provides custom application information.

intermediate

How do you enable all Actuator endpoints in a Spring Boot application?

Set management.endpoints.web.exposure.include=* in application.properties or application.yml to expose all endpoints over HTTP.

intermediate

What security considerations should you keep in mind with Actuator endpoints?

Actuator endpoints can expose sensitive data. Always secure them using authentication and limit exposure to trusted users or networks.

beginner

Explain the difference between 'health' and 'info' Actuator endpoints.

/health shows the current health status of the app (like UP or DOWN).
/info shows static or custom information about the app, like version or build details.

Which Actuator endpoint shows the current health status of the application?

A /env

B /metrics

C /info

D /health

The /health endpoint provides the current health status like UP or DOWN.

How do you expose all Actuator endpoints over HTTP?

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

B spring.actuator.enabled=true

C management.endpoint.all.enabled=true

D spring.boot.actuator.expose=all

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

Which endpoint would you use to see JVM memory usage?

A /info

B /health

C /metrics

D /loggers

/metrics shows JVM memory and other performance metrics.

Why should Actuator endpoints be secured?

A They can expose sensitive information

B They require a database connection

C They only work with security enabled

D They slow down the app if unsecured

Unsecured endpoints may reveal sensitive data about the app.

Which Actuator endpoint provides custom application details like version or build info?

A /health

B /info

C /metrics

D /beans

/info is used to show custom app information.

Describe the main Actuator endpoints and what information each provides.

Think about monitoring app health, performance data, and app info.

Explain how to safely expose Actuator endpoints in a production Spring Boot app.

Consider both enabling endpoints and protecting them.

Practice

1. What is the main purpose of Spring Boot Actuator endpoints?

easy

A. To handle user authentication and authorization

B. To serve static web content like images and CSS

C. To manage database connections automatically

D. To provide information about the application's health and status

Solution

1. Step 1: Understand Actuator endpoints role

   Actuator endpoints are designed to give quick info about the app's health and status.

2. Step 2: Compare with other options

   Authentication, database management, and static content serving are not the main roles of Actuator.

3. Final Answer:

   To provide information about the application's health and status -> Option D

4. Quick Check:

   Actuator endpoints = app health info [OK]

Hint: Remember: Actuator = app health and metrics info [OK]

Common Mistakes:

• Confusing Actuator with security features
• Thinking Actuator manages database connections
• Assuming Actuator serves static files

2. Which property enables the exposure of all Actuator endpoints in Spring Boot?

easy

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

B. spring.boot.actuator.enabled=true

C. management.endpoint.health.enabled=true

D. server.port=8080

Solution

1. Step 1: Identify property to expose endpoints

   The property management.endpoints.web.exposure.include=* exposes all Actuator endpoints.

2. Step 2: Check other options

   spring.boot.actuator.enabled is not a valid property; health endpoint enabling is specific, and server.port sets the server port.

3. Final Answer:

   management.endpoints.web.exposure.include=* -> Option A

4. Quick Check:

   Expose all endpoints = management.endpoints.web.exposure.include=* [OK]

Hint: Use '*' in exposure.include to enable all endpoints [OK]

Common Mistakes:

• Using incorrect property names
• Confusing enabling endpoints with enabling server
• Trying to enable endpoints individually without exposure property

3. Given the following configuration:

management.endpoints.web.exposure.include=health,info

Which endpoints will be accessible via HTTP?

medium

A. Only /health and /info endpoints

B. All Actuator endpoints

C. No endpoints are accessible

D. Only /metrics endpoint

Solution

1. Step 1: Read the exposure.include property

   The property lists health and info, so only these endpoints are exposed.

2. Step 2: Understand what exposure.include controls

   It controls which endpoints are accessible via HTTP; others remain hidden.

3. Final Answer:

   Only /health and /info endpoints -> Option A

4. Quick Check:

   Exposure include = health,info means only those endpoints [OK]

Hint: Check exposure.include list to know accessible endpoints [OK]

Common Mistakes:

• Assuming all endpoints are exposed by default
• Confusing exposure.include with enabling endpoints
• Thinking metrics endpoint is included without listing it

4. You configured management.endpoints.web.exposure.include=health,metrics but the /metrics endpoint returns 404. What is the likely cause?

medium

A. The metrics endpoint is disabled by default and needs explicit enabling

B. The health endpoint is conflicting with metrics

C. The application is missing the actuator dependency

D. The server port is incorrect

Solution

1. Step 1: Check if actuator dependency is present

   Without the actuator library, endpoints like /metrics won't exist, causing 404.

2. Step 2: Verify other options

   Metrics endpoint is enabled by exposure.include; health does not conflict; server port affects access but not endpoint existence.

3. Final Answer:

   The application is missing the actuator dependency -> Option C

4. Quick Check:

   Missing actuator dependency = 404 on endpoints [OK]

Hint: Always add actuator dependency to use Actuator endpoints [OK]

Common Mistakes:

• Assuming endpoints work without actuator dependency
• Blaming port or conflicts instead of missing library
• Thinking exposure.include enables endpoints without actuator

5. You want to monitor your Spring Boot app's health, info, and metrics endpoints but only expose health and info publicly. How do you configure this securely?

hard

A. Set management.endpoints.web.exposure.include=health,info,metrics and disable security

B. Set management.endpoints.web.exposure.include=health,info and secure /metrics with authentication

C. Expose all endpoints with * and rely on firewall rules

D. Disable all endpoints except metrics

Solution

1. Step 1: Expose only health and info endpoints publicly

   Use management.endpoints.web.exposure.include=health,info to expose only those endpoints.

2. Step 2: Secure metrics endpoint separately

   Keep metrics endpoint enabled internally and protect it with authentication or network rules.

3. Final Answer:

   Set management.endpoints.web.exposure.include=health,info and secure /metrics with authentication -> Option B

4. Quick Check:

   Expose only needed endpoints publicly, secure others [OK]

Hint: Expose only needed endpoints publicly; secure sensitive ones [OK]

Common Mistakes:

• Exposing all endpoints without security
• Disabling security to simplify access
• Exposing metrics publicly without protection