Documentation Index
Fetch the complete documentation index at: https://docs.localops.co/llms.txt
Use this file to discover all available pages before exploring further.
A complete walkthrough of instrumenting a Java service using the official
Prometheus Java client library (client_java v1.x).
See the overview for the general approach.
1. Add the Prometheus client dependency
Add these dependencies to your pom.xml (Maven):
<dependency>
<groupId>io.prometheus</groupId>
<artifactId>prometheus-metrics-core</artifactId>
<version>1.3.6</version>
</dependency>
<dependency>
<groupId>io.prometheus</groupId>
<artifactId>prometheus-metrics-instrumentation-jvm</artifactId>
<version>1.3.6</version>
</dependency>
<dependency>
<groupId>io.prometheus</groupId>
<artifactId>prometheus-metrics-exporter-httpserver</artifactId>
<version>1.3.6</version>
</dependency>
build.gradle):
implementation 'io.prometheus:prometheus-metrics-core:1.3.6'
implementation 'io.prometheus:prometheus-metrics-instrumentation-jvm:1.3.6'
implementation 'io.prometheus:prometheus-metrics-exporter-httpserver:1.3.6'
2. Register custom metrics and expose /metrics
Register default JVM metrics, define your own custom counters/gauges, and start an HTTP server that exposes them on
/metrics:
import io.prometheus.metrics.core.metrics.Counter;
import io.prometheus.metrics.exporter.httpserver.HTTPServer;
import io.prometheus.metrics.instrumentation.jvm.JvmMetrics;
public class App {
static final Counter emailsSent = Counter.builder()
.name("emails_sent_total")
.help("Total number of emails sent")
.labelNames("status")
.register();
public static void main(String[] args) throws Exception {
// Register out-of-the-box JVM metrics (memory, GC, threads, classloader, etc.)
JvmMetrics.builder().register();
// Start the metrics HTTP server on port 9090
HTTPServer.builder()
.port(9090)
.buildAndStart();
// Increment your custom metric anywhere in your code
emailsSent.labelValues("success").inc();
}
}
9090 that responds to GET /metrics in Prometheus exposition format —
including JVM metrics like jvm_memory_used_bytes, jvm_gc_pause_seconds, jvm_threads_live_threads, plus your
custom emails_sent_total.
If you’re using Spring Boot, the typical approach is Spring Boot Actuator + Micrometer’s Prometheus registry. Add
io.micrometer:micrometer-registry-prometheus and set management.endpoints.web.exposure.include=prometheus in
application.properties. The /actuator/prometheus endpoint is then exposed on your main service port.
3. Declare the metrics endpoint in ops.json
{
"metrics": {
"endpoint": "/metrics",
"interval": 15,
"port": 9090
}
}
http://<your-service>:9090/metrics every 15 seconds and make every metric — JVM and custom
— available in Grafana.
Instead of building JVM dashboards from scratch, import a battle-tested community dashboard from
grafana.com/grafana/dashboards.
| Dashboard | ID | Notes |
|---|
| JVM (Micrometer) | 4701 | Most popular JVM dashboard. Built for Micrometer but most panels work with client_java v1.x since metric names like jvm_memory_used_bytes and jvm_threads_live_threads overlap. |
| JVM (Micrometer) — alternative | 8898 | Alternative JVM dashboard, also Micrometer-based. |
| JVM SpringBoot3 | 22108 | For Spring Boot 3.x apps using Actuator + Micrometer. |
emails_sent_total, etc.) can be charted alongside in the same or a separate dashboard.
