This repository contains several examples demonstrating how to instrument Java applications for Prometheus.

Table of Contents

• Running the demo
• JMX exporter
• client_java
• MicroProfile Metrics
• Micrometer
• License

Running the demo

All examples can be packaged as container images for easy deployment.

Create a shared network for all the containers.

docker network create prometheus

Start the applications.

(cd jmx_exporter && docker-compose up -d)
docker run --rm -d -p 8081:8080 --network prometheus --name client_java quay.io/simonpasquier/client_java
docker run --rm -d -p 8082:8080 --network prometheus --name mp_metrics quay.io/simonpasquier/mp_metrics
docker run --rm -d -p 8083:8080 --network prometheus --name micrometer quay.io/simonpasquier/micrometer
docker run --rm -d -v $PWD/prometheus/prometheus.yml:/etc/prometheus/prometheus.yml -p 9090:9090 --network prometheus --name prometheus prom/prometheus:latest

Verify that everything is running fine.

docker ps

You can access the Prometheus UI at http://localhost:9090/.

You can generate some load

docker run --rm -d --network prometheus --name loadtest quay.io/simonpasquier/loadtest \
    -concurrent 10 -rate 5 \
    -uri http://client_java:8080/hello \
    -uri http://mp_metrics:8080/hello \
    -uri http://micrometer:8080/hello

JMX exporter

Retrieve the metrics exposed by the endpoint:

curl http://localhost:9098/metrics

In the Prometheus UI, query the percentage of CPU consumed by Kafka (including the exporter):

100 * rate(process_cpu_seconds_total{job="kafka"}[1m])

client_java

Retrieve the metrics exposed by the endpoint:

curl http://localhost:8081/metrics

In the Prometheus UI, query the resident memory consumed by the application:

process_resident_memory_bytes{job="web"}

In the Prometheus UI, query the total percentage of CPU consumed for all applications instrumented with the Prometheus libraries:

100 * sum by(job) (rate(process_cpu_seconds_total[1m]))

MicroProfile Metrics

Retrieve the metrics exposed by the endpoint:

curl http://localhost:8082/metrics

Retrieve only the base metrics exposed by the endpoint (base can be replaced by vendor or application):

curl http://localhost:8082/metrics/base

Retrieve the metric metadata:

curl -H "Accept: application/json" -XOPTIONS http://localhost:8082/metrics

In the Prometheus UI, query the ratio of request failures:

100 * rate(application:requests_failed_total[1m]) / rate(application:requests_total[1m])

Query all the response time percentiles:

application:request_duration_seconds

Query the 99th-percentile response time:

application:request_duration_seconds{quantile="0.99"}

Micrometer

Retrieve the metrics exposed by the endpoint:

curl http://localhost:8083/actuator/prometheus

In the Prometheus UI, query the rate of requests by status code for the /hello endpoint:

sum by (job,status) (rate(http_server_requests_seconds_count{uri="/hello"}[1m]))

Query the 99th-percentile response time for the all endpoints:

histogram_quantile(0.99, sum by (job,uri,le) (rate(http_server_requests_seconds_bucket[1m])))

Query the rate of request failures for the /hello endpoint:

100 * sum by (job) (rate(http_server_requests_seconds_count{uri="/hello",status=~"5.+"}[1m])) / sum by (job) (rate(http_server_requests_seconds_count{uri="/hello"}[1m]))

License

Apache License 2.0, see LICENSE.