Java Interview Preparation
Actuator and Monitoring Interview Questions
Health, metrics, probes, observability, Prometheus, Grafana, and monitoring security.
Actuator and Monitoring Interview Focus
Health, metrics, probes, observability, Prometheus, Grafana, and monitoring security.
Interview questions
1. What is Spring Boot Actuator? Beginner
Spring Boot Actuator adds production-focused endpoints for health, metrics, environment information, mappings, and other operational data. It helps teams monitor an application without writing every endpoint themselves.
2. What are the commonly used Actuator endpoints? Beginner
Actuator exposes operational endpoints such as health, info, metrics, loggers, and mappings. Expose only the endpoints needed by operators and protect them with authentication and network controls.
3. How do you expose Actuator endpoints? Beginner
Actuator exposes operational endpoints such as health, info, metrics, loggers, and mappings. Expose only the endpoints needed by operators and protect them with authentication and network controls.
4. How do you create a custom health indicator? Intermediate
Actuator and monitoring make application health, metrics, and operational behaviour visible to development and operations teams. Start with the definition, understand which problem it solves, and then apply it in a small example. In an interview, explain the normal use, the main trade-off, and one practical mistake to avoid.
5. What is the difference between liveness and readiness probes? Intermediate
Liveness answers whether the process should be restarted. Readiness answers whether the instance should receive traffic. Keeping these checks separate helps orchestrators react correctly during startup and failure.
6. How do you collect application metrics? Intermediate
Micrometer provides a vendor-neutral metrics API used by Spring Boot. Prometheus can scrape exported metrics, while Grafana visualizes them and supports dashboards and alerts.
7. What is Micrometer? Intermediate
Micrometer provides a vendor-neutral metrics API used by Spring Boot. Prometheus can scrape exported metrics, while Grafana visualizes them and supports dashboards and alerts.
8. How do you integrate Spring Boot with Prometheus and Grafana? Advanced
Micrometer provides a vendor-neutral metrics API used by Spring Boot. Prometheus can scrape exported metrics, while Grafana visualizes them and supports dashboards and alerts.
9. How do you monitor JVM memory and garbage collection? Advanced
Expose Micrometer and Actuator metrics, then watch heap usage, GC pauses, thread counts, active connections, idle connections, and acquisition time. Alerts should focus on sustained trends and user impact.
10. How do you monitor database connection pools? Advanced
Expose Micrometer and Actuator metrics, then watch heap usage, GC pauses, thread counts, active connections, idle connections, and acquisition time. Alerts should focus on sustained trends and user impact.
11. How do you secure monitoring endpoints? Advanced
Actuator and monitoring make application health, metrics, and operational behaviour visible to development and operations teams. Start with the definition, understand which problem it solves, and then apply it in a small example. In an interview, explain the normal use, the main trade-off, and one practical mistake to avoid.
How to Prepare for Java Technical Interviews
Use this Java technical interview question bank to revise core concepts and practise explaining your decisions clearly. The questions cover Java fundamentals, object-oriented programming, collections, exceptions, multithreading, Spring Boot, Hibernate, databases, and other topics used in real software development interviews.
Start with the fundamentals, then move to scenario-based questions and advanced topics. Filter questions by difficulty to build confidence gradually. A strong answer should define the concept, explain why it matters, and include a practical example when appropriate.
Continue your preparation with the Java tutorials, or explore all interview preparation tracks for managerial and company-focused questions.