How to Monitor Spring Boot Applications with Prometheus and Grafana

Introduction

With the rise of microservice architecture, monitoring services becomes crucial. Prometheus is an open‑source monitoring and alerting tool with powerful data collection, storage and query capabilities. Combining Spring Boot with Prometheus enables real‑time monitoring of Spring Boot applications.

1. Prometheus Overview

Prometheus is an open‑source system monitoring and alerting toolkit that collects and stores metrics, provides a powerful query language, and includes a Prometheus Server as the core component.

Official site: https://prometheus.io/

GitHub: https://github.com/prometheus/prometheus

2. Spring Boot Actuator

Spring Boot Actuator provides a set of endpoints (e.g., /health, /info, /metrics) for exposing internal application information such as health status, configuration, and metrics.

3. Integrating Prometheus with Spring Boot

3.1 Add Dependencies

Add Spring Boot Actuator and Micrometer Prometheus Registry to the project.

<dependencies>
  <!-- Spring Boot Actuator -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
    <version>2.7.15</version>
  </dependency>
  <!-- Micrometer Prometheus Registry -->
  <dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-registry-prometheus</artifactId>
    <version>1.9.14</version>
  </dependency>
</dependencies>

3.2 Configure Actuator

management:
  endpoints:
    web:
      exposure:
        include: '*'
metrics:
  export:
    prometheus:
      enabled: true

Other configuration properties:

management.endpoints.web.exposure.include=*
management.metrics.export.prometheus.enabled=true
management.endpoints.web.base-path="/status"
management.endpoints.server.request.metric-name="application:request"
management.server.port=10001

3.3 Start Prometheus Server

Docker commands to pull and run Prometheus.

docker pull prom/prometheus
docker run --name prometheus -d -p 9090:9090 prom/prometheus

Mount custom prometheus.yml if needed.

docker run -d --name prometheus -p 9090:9090 -v D:\developsoft\docker\DockerDesktopWSL\data\prometheus\prometheus.yml:/etc/prometheus/prometheus.yml prom/prometheus

Configure prometheus.yml to scrape the Spring Boot application.

scrape_configs:
  - job_name: 'spring-boot-application'
    metrics_path: 'prometheus-demo/actuator/prometheus'
    scrape_interval: 15s
    static_configs:
      - targets: ['192.168.10.108:8091']

Access metrics at /actuator/prometheus.

4. Visualizing Metrics with Grafana

4.1 Install Grafana

docker pull grafana/grafana
docker run -d --name=grafana -p 3000:3000 grafana/grafana

Open http://localhost:3000 (default credentials admin/admin).

4.2 Configure Data Source

In Grafana, add Prometheus as a data source pointing to the Prometheus server address.

4.3 Create Dashboard

Create a new dashboard, add panels, select Prometheus as the source, and write PromQL queries to visualize metrics.

5. Custom Monitoring Metrics

5.1 Add Custom Metrics

Use Micrometer API to define custom counters.

import io.micrometer.core.instrument.Counter;
import io.micrometer.core.instrument.MeterRegistry;

@RestController
public class CustomMetricsController {
    private final Counter ordersCounter;

    public CustomMetricsController(MeterRegistry registry) {
        this.ordersCounter = Counter.builder("orders_count")
            .description("The total number of orders")
            .register(registry);
    }

    @GetMapping("/order")
    public String createOrder() {
        ordersCounter.increment();
        return "Order created";
    }
}

5.2 Display Custom Metrics in Grafana

Custom metrics appear like any other Prometheus metric and can be added to Grafana panels using PromQL queries.