Monitor java application using prometheus

To monitor a JAVA (spring boot) application you need to add some prometheus dependencies in your JAVA code. For more information about spring boot and dependencies follow the link below:-

https://docs.spring.io/spring-boot/docs/current/reference/html/production-ready-features.html

For serving metrics in java spring boot application we need to add dependencies in our codebase, in my case I am having a spring boot application on gradle too, for exposing metrics add dependencies in build.gradle file.

Here is an example:-

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web") {
        exclude module: "spring-boot-starter-nginx"
    }
    compile("org.springframework.boot:spring-boot-starter-jetty")
    compile("org.springframework.boot:spring-boot-starter-actuator")

    //Prometheus
    compile 'io.prometheus:simpleclient_spring_boot:0.0.21'
    compile 'io.prometheus:simpleclient_servlet:0.0.21'
    compile 'io.prometheus:simpleclient_hotspot:0.0.21'
}

After adding this make the build of your project and run the application. Suppose your application is running on port no. 8080 and it is exposing its metrics on path /prometheus then you need to add it to your prometheus.yml file and then create a dashboard for it in grafana.

After adding the application ip and port no. in your prometheus.yml for monitoring, your config file should look like this

            
global:
  scrape_interval: 15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: 'my-java-app'
    scrape_interval: 5s
    metrics_path: '/prometheus'
    static_configs:
     - targets: ['your-ip:8080']