Monitoring JVM metrics with ClickStack

Monitoring JVM with ClickStack

Monitoring JVM Metrics with ClickStack

TL;DR

Monitor JVM applications in ClickStack using the OpenTelemetry Java agent. Includes a demo dataset and pre-built dashboard.

Integration with existing JVM application

This section covers configuring your existing JVM application to send metrics to ClickStack using the OpenTelemetry Java agent.

If you would like to test the integration before configuring your production setup, you can test with our demo dataset in the demo dataset section.

• ClickStack instance running
• Existing Java application (Java 8+)
• Access to modify JVM startup arguments

1. Get ClickStack API key

   The OpenTelemetry Java agent sends data to ClickStack’s OTLP endpoint, which requires authentication.

   1. Open HyperDX at your ClickStack URL (e.g., http://localhost:8080)
   2. Create an account or log in if needed
   3. Navigate to Team Settings → API Keys
   4. Copy your Ingestion API Key
2. Download OpenTelemetry Java agent

   Download the OpenTelemetry Java agent JAR file:

   curl -L -O https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/download/v2.22.0/opentelemetry-javaagent.jar
   

   This downloads the agent to your current directory. You can place it wherever makes sense for your deployment (e.g., /opt/opentelemetry/ or alongside your application JAR).

3. Configure JVM startup arguments

   Add the Java agent to your JVM startup command. The agent automatically collects JVM metrics and sends them to ClickStack.

   java -javaagent:opentelemetry-javaagent.jar \
     -Dotel.service.name=my-java-app \
     -Dotel.exporter.otlp.endpoint=http://localhost:4318 \
     -Dotel.exporter.otlp.protocol=http/protobuf \
     -Dotel.exporter.otlp.headers="authorization=YOUR_API_KEY" \
     -Dotel.metrics.exporter=otlp \
     -Dotel.logs.exporter=none \
     -Dotel.traces.exporter=none \
     -jar my-application.jar
   

   Replace the following:

   • opentelemetry-javaagent.jar → Full path to the agent JAR (e.g., /opt/opentelemetry/opentelemetry-javaagent.jar)
   • my-java-app → A meaningful name for your service (e.g., payment-service, user-api)
   • YOUR_API_KEY → Your ClickStack API key from the command above
   • my-application.jar → Your application’s JAR file name
   • http://localhost:4318 → Your ClickStack endpoint (use localhost:4318 if ClickStack runs on the same machine, otherwise use http://your-clickstack-host:4318)

   Alternatively, use environment variables:

   export JAVA_TOOL_OPTIONS="-javaagent:opentelemetry-javaagent.jar"
   export OTEL_SERVICE_NAME="my-java-app"
   export OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:4318"
   export OTEL_EXPORTER_OTLP_PROTOCOL="http/protobuf"
   export OTEL_EXPORTER_OTLP_HEADERS="authorization=YOUR_API_KEY"
   export OTEL_METRICS_EXPORTER="otlp"
   export OTEL_LOGS_EXPORTER="none"
   export OTEL_TRACES_EXPORTER="none"
   
   java -jar my-application.jar
   

   Replace the following:

   • opentelemetry-javaagent.jar → Full path to the agent JAR
   • my-java-app → Your service name
   • YOUR_API_KEY → Your ClickStack API key
   • http://localhost:4318 → Your ClickStack endpoint
   • my-application.jar → Your application’s JAR file name

   The OpenTelemetry Java agent automatically collects these JVM metrics:

   • Memory: jvm.memory.used, jvm.memory.limit, jvm.memory.committed, jvm.memory.used_after_last_gc
   • Garbage Collection: jvm.gc.duration
   • Threads: jvm.thread.count
   • Classes: jvm.class.count, jvm.class.loaded, jvm.class.unloaded
   • CPU: jvm.cpu.time, jvm.cpu.count
4. Verify metrics in HyperDX

   Once your application is running with the agent, verify metrics are flowing to ClickStack:

   1. Open HyperDX at http://localhost:8080 (or your ClickStack URL)
   2. Navigate to Chart Explorer
   3. Search for metrics starting with jvm. (e.g., jvm.memory.used, jvm.gc.duration, jvm.thread.count)

Demo dataset

For users who want to test the JVM metrics integration before instrumenting their applications, we provide a sample dataset with pre-generated metrics showing realistic JVM behavior from a medium-sized microservice with steady moderate traffic.

1. Download the sample dataset

   # Download gauge metrics (memory, threads, CPU, classes)
   curl -O https://datasets-documentation.s3.eu-west-3.amazonaws.com/clickstack-integrations/jvm/jvm-metrics-gauge.jsonl
   
   # Download sum metrics (GC events)
   curl -O https://datasets-documentation.s3.eu-west-3.amazonaws.com/clickstack-integrations/jvm/jvm-metrics-sum.jsonl
   

   The dataset includes 24 hours of JVM metrics showing:

   • Heap memory growth with periodic garbage collection events
   • Thread count variations
   • Realistic GC pause times
   • Class loading activity
   • CPU utilization patterns
2. Start ClickStack

   If you don’t already have ClickStack running:

   docker run -d --name clickstack \
     -p 8080:8080 -p 4317:4317 -p 4318:4318 \
     clickhouse/clickstack-all-in-one:latest
   

   Wait a few moments for ClickStack to fully start up.

3. Import the demo dataset

   # Import gauge metrics (memory, threads, CPU, classes)
   docker exec -i clickstack clickhouse-client --query="
     INSERT INTO default.otel_metrics_gauge FORMAT JSONEachRow
   " < jvm-metrics-gauge.jsonl
   
   # Import sum metrics (GC events)
   docker exec -i clickstack clickhouse-client --query="
     INSERT INTO default.otel_metrics_sum FORMAT JSONEachRow
   " < jvm-metrics-sum.jsonl
   

   This imports the metrics directly into ClickStack’s metrics tables.

4. Verify the demo data

   Once imported:

   1. Open HyperDX at http://localhost:8080 and log in (create an account if needed)
   2. Navigate to the Search view and set source to Metrics
   3. Set the time range to 2025-12-06 14:00:00 - 2025-12-09 14:00:00
   4. Search for jvm.memory.used or jvm.gc.duration

   You should see metrics for the demo service.

   Timezone Display

   HyperDX displays timestamps in your browser’s local timezone. The demo data spans 2025-12-07 14:00:00 - 2025-12-08 14:00:00 (UTC). Set your time range to 2025-12-06 14:00:00 - 2025-12-09 14:00:00 to ensure you see the demo metrics regardless of your location. Once you see the metrics, you can narrow the range to a 24-hour period for clearer visualizations.

Dashboards and visualization

To help you monitor JVM applications with ClickStack, we provide a pre-built dashboard with essential visualizations for JVM metrics.

1. the dashboard configuration

2. Import the pre-built dashboard

   1. Open HyperDX and navigate to the Dashboards section
   2. Click Import Dashboard in the upper right corner under the ellipses

   3. Upload the jvm-metrics-dashboard.json file and click Finish Import
3. View the dashboard

   The dashboard will be created with all visualizations pre-configured:

   For the demo dataset, set the time range to 2025-12-07 14:00:00 - 2025-12-08 14:00:00 (UTC). Adjust based on your local timezone.

Troubleshooting

Agent not starting

Verify the agent JAR exists:

ls -lh /path/to/opentelemetry-javaagent.jar

Check Java version compatibility (requires Java 8+):

java -version

Look for agent startup log message: When your application starts, you should see:

[otel.javaagent] OpenTelemetry Javaagent v2.22.0 started

No metrics appearing in HyperDX

Verify ClickStack is running and accessible:

docker ps | grep clickstack
curl -v http://localhost:4318/v1/metrics

Check that metrics exporter is configured:

# If using environment variables, verify:
echo $OTEL_METRICS_EXPORTER
# Should output: otlp

Check application logs for OpenTelemetry errors: Look for any error messages related to OpenTelemetry or OTLP export failures in your application logs.

Verify network connectivity: If ClickStack is on a remote host, ensure port 4318 is accessible from your application server.

Verify agent version: Ensure you’re using the latest stable agent version (currently 2.22.0), as newer versions often include performance improvements.

Next steps

• Set up alerts for critical metrics like high heap usage, frequent GC pauses, or thread exhaustion
• Explore other ClickStack integrations to unify your observability data

Going to production

This guide demonstrates configuring the OpenTelemetry Java agent for local testing. For production deployments, include the agent JAR in your container images and configure via environment variables for easier management. For larger environments with many JVM instances, deploy a centralized OpenTelemetry Collector to batch and forward metrics from multiple applications instead of sending directly to ClickStack.

See Ingesting with OpenTelemetry for production deployment patterns and collector configuration examples.