How to Integrate Prometheus and Grafana with Spring Boot for Real‑Time Monitoring

Environment: springboot2.4.12 + prometheus1.6.7 + grafana7.5.7

What is Prometheus

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

Prometheus stores time‑series data, i.e., collections of data points identified by the same metric name and set of key/value labels over time.

A time series is defined by a metric name and a set of key/value labels; series with identical name and labels belong to the same time series.

Dependency Configuration

<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:

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

Access Prometheus actuator endpoint (e.g., http://localhost:9999/actuator/prometheus).

Prometheus Installation and Configuration

Download Prometheus from the official site.

Configure scrape_configs:

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 monitored 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 and Configuration

Download Grafana, start the service (default login admin/admin).

Add Prometheus as a data source and explore the collected metrics, including the custom visitor counter.

Monitoring Database Connection Pool

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