bodyakin / spring-prometheus-poc

Proof of concept of Spring and Prometheus

Proof of concept Spring Boot application with Micrometer, MongoDB and Prometheus monitoring

Run MongoDB, Application, Prometheus and Grafana:

docker-compose up -d

Prometheus http://localhost:9090

Grafana http://localhost:3000 admin/admin

To rebuild spring application image run

./gradlew bootBuildImage

and change docker-compose.yml

services:
  spring:
    image: docker.io/library/spring-prometheus:0.0.1-SNAPSHOT

@Timed annotation

Using @Timed annotation it is possible to observe the latency distribution of method invocations. I have annotated method getAllBooks() in BookService and made artificial delay for each request. The parameter `histogram = true' makes additional metrics for building a histogram of request duration.

    @Timed(value = "book_get_all", histogram = true)
    public List<Book> getAllBooks() {
        randomDelay();
        return repository.findAll();
    }

Execute several times

curl localhost:8080/books

and you could see a bunch of new metrics there http://localhost:8080/actuator/prometheus

...
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.156587348",} 0.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.178956969",} 0.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.20132659",} 0.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.223696211",} 0.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.246065832",} 0.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.268435456",} 0.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.357913941",} 0.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.447392426",} 2.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.536870911",} 2.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.626349396",} 4.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.715827881",} 4.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.805306366",} 6.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.894784851",} 6.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="0.984263336",} 6.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="1.073741824",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="1.431655765",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="1.789569706",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="2.147483647",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="2.505397588",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="2.863311529",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="3.22122547",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="3.579139411",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="3.937053352",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="4.294967296",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="5.726623061",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="7.158278826",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="8.589934591",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="10.021590356",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="11.453246121",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="12.884901886",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="14.316557651",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="15.748213416",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="17.179869184",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="22.906492245",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="28.633115306",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="30.0",} 7.0
book_get_all_seconds_bucket{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",le="+Inf",} 7.0
book_get_all_seconds_count{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",} 7.0
book_get_all_seconds_sum{application="demoservice",class="com.bodyakin.springprometheus.services.BookService",exception="none",method="getAllBooks",} 4.627468766

Visualization of these metrics you can find in Request duration Grafana dashboard

@Counted

    @Counted(value = "book_get")
    public Book getBookById(String id) {
        return repository.findById(id)
                .orElseThrow(IllegalArgumentException::new);
    }

Having response from localhost:8080/books we can request book by its id, for instance

curl localhost:8080/books/5eaf01af72254072a79d82b8

Usually we are interested in rate and increase of count metrics. See Method invocations dashboard