How to Integrate Prometheus Monitoring into Spring Boot with Grafana

What is Prometheus

Prometheus is an open‑source service monitoring system and time‑series database.

It stores time‑series data identified by a metric name and a set of key/value labels.

Configuration Dependencies

<dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
  </dependency>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-registry-prometheus</artifactId>
  </dependency>
</dependencies>

spring:
  application:
    name: app-prometheus
---
management:
  server:
    port: 9999
  endpoints:
    enabled-by-default: true
    web:
      exposure:
        include: '*'

Register MeterRegistry

@Bean
public MeterRegistryCustomizer<MeterRegistry> configurer(@Value("${spring.application.name}") String name) {
  return registry -> registry.config().commonTags("application", name);
}

Access Prometheus actuator endpoint at http://localhost:9999/actuator/prometheus.

Prometheus Installation & Configuration

Download Prometheus from the official site.

Configure prometheus.yml:

scrape_configs:
  - job_name: 'app-prometheus'
    scrape_interval: 5s
    metrics_path: '/actuator/prometheus'
    static_configs:
    - targets: ['localhost:9999']

Start Prometheus and open its UI to view collected metrics.

Custom Meter Example

@Resource
private MeterRegistry registry;
private Counter counter;

@PostConstruct
public void init() {
  counter = this.registry.counter("visitor");
}

@GetMapping("/count")
public String count() {
  this.counter.increment();
  return "访问次数：" + this.counter.count();
}

Invoke the /count endpoint several times and observe the incremented metric in Prometheus.

Grafana Installation & Configuration

Download and start Grafana (default credentials admin/admin).

Add Prometheus as a data source pointing to http://localhost:9090.

Create dashboards to visualize the visitor metric and other application metrics.

Monitoring Database Connection Pool

When using HikariCP in the Spring Boot project, Grafana can automatically display database connection pool statistics after adding the Prometheus data source.

All steps complete – you now have a fully monitored Spring Boot application with Prometheus and Grafana.