Health endpoint customization in Spring Boot - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of the custom health indicator?

Given this Spring Boot custom health indicator code, what will the /actuator/health endpoint show when the application is running?

Spring Boot

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;

@Component
public class CustomHealthIndicator implements HealthIndicator {
    @Override
    public Health health() {
        int errorCode = check(); // perform some specific health check
        if (errorCode != 0) {
            return Health.down().withDetail("Error Code", errorCode).build();
        }
        return Health.up().withDetail("Custom Info", "All systems go").build();
    }

    private int check() {
        return 0; // no error
    }
}

A {"status":"UP","details":{"Custom Info":"All systems go"}}

B {"status":"UP"}

C {"status":"DOWN","details":{"Error Code":0}}

D {"status":"DOWN","details":{"Custom Info":"All systems go"}}

💡 Hint

Look at the check() method return value and how it affects the health status.

The check() method returns 0, so the health indicator returns UP status with the detail 'Custom Info'.

📝 Syntax

intermediate

Which option correctly disables the default health endpoint?

You want to disable the default /actuator/health endpoint in Spring Boot. Which configuration property and value correctly achieves this?

A management.endpoints.health.enabled=false

B management.health.enabled=false

C management.endpoint.health.enabled=false

D management.endpoint.healths.enabled=false

💡 Hint

Check the exact property name for enabling or disabling endpoints in Spring Boot actuator.

The correct property to disable the health endpoint is management.endpoint.health.enabled=false.

🔧 Debug

advanced

Why does the custom health indicator not appear in /actuator/health?

You created a custom HealthIndicator bean but it does not show in the /actuator/health response. What is the most likely cause?

Spring Boot

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;

@Component
public class MyHealthIndicator implements HealthIndicator {
    @Override
    public Health health() {
        return Health.up().withDetail("status", "ok").build();
    }
}

A The application is missing spring-boot-starter-actuator dependency.

B The management.endpoint.health.show-details property is set to 'never'.

C The custom HealthIndicator class does not implement HealthIndicator interface.

D The custom HealthIndicator class is missing @Component annotation.

💡 Hint

Check the actuator configuration for health details visibility.

If 'management.endpoint.health.show-details' is set to 'never', custom health details are hidden from the health endpoint response.

❓ state_output

advanced

What is the health status after simulating a failure?

Consider this custom health indicator that simulates a failure when a flag is true. What will the /actuator/health endpoint show if simulateFailure is true?

Spring Boot

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;

@Component
public class SimulatedHealthIndicator implements HealthIndicator {
    private boolean simulateFailure = true;

    @Override
    public Health health() {
        if (simulateFailure) {
            return Health.down().withDetail("Failure", "Simulated failure").build();
        }
        return Health.up().build();
    }
}

A {"status":"UNKNOWN"}

B {"status":"UP"}

C {"status":"DOWN"}

D {"status":"DOWN","details":{"Failure":"Simulated failure"}}

💡 Hint

Look at the simulateFailure flag and how it affects the health status.

When simulateFailure is true, the health indicator returns DOWN status with the failure detail.

🧠 Conceptual

expert

Which statement about health endpoint customization is true?

Select the correct statement about customizing the Spring Boot health endpoint.

A HealthIndicator beans are aggregated; the health endpoint combines all indicators into one response.

B Disabling the health endpoint requires removing the spring-boot-starter-actuator dependency.

C You must extend AbstractHealthIndicator to create a custom health indicator; implementing HealthIndicator is not enough.

D Custom HealthIndicator beans automatically override the default health checks and replace them entirely.

💡 Hint

Think about how Spring Boot combines multiple health indicators.

Spring Boot aggregates all HealthIndicator beans and combines their results into a single health endpoint response.