> ## Content Index > Fetch the complete content index at: https://devopscube.com/llms.txt > Use this file to discover other available public pages before exploring further. # How to Setup Prometheus JMX Exporter on Kubernetes (Detailed Guide) - URL: https://devopscube.com/prometheus-jmx-exporter-on-kubernetes/ - Published: 2024-06-26T12:10:52.000Z - Updated: 2025-03-15T07:01:13.000Z - Author: Bibin Wilson - Tags: HOW TO GUIDES, #arunlal, Kubernetes, MONITORING, #Migrated-1741795015845, #wp, #wp-post, #Import 2025-03-12 15:57, #blog In this blog, we will look at the setup and configuration of the Prometheus **JMX Exporter** on a Kubernetes using a Java application. To better understand the JMX exporter, we will use a Spring Boot Java application and export all the JMX metrics to the Prometheus server. By the end of this guide, you will learn to: 1. Setup JMX Exporter with Java application image 2. Export JMX metrics to the Prometheus server 3. Scrape JMX metrics of the app using Prometheus SD configs. 4. Validate and query JMX metrics from the Prometheus dashboard. Let’s dive right in. ## Prerequisites For setting up and testing this setup, you should have the following. 1. [Kubernetes cluster](https://devopscube.com/setup-kubernetes-cluster-kubeadm/) with deployment permissions. 2. [Prometheus Server running on Kubernetes](https://devopscube.com/setup-prometheus-monitoring-on-kubernetes/). ## JMX Exporter First, let's understand how the JMX exporter works. The following image shows the JMX Exporter workflow when deploying it on Kubernetes. ![JMX Exporter workflow when deploying it on Kubernetes.](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/jmx-on-kubernetes-1-1.gif) The MBean (Managed Bean) server, located within the Java Virtual Machine (JVM) of a Java application, acts as a repository for data related to the application's health and performance. The MBean component exposes the application metrics such as status, actions, and operation information. Java agents can access the Mbean server and get the health and performance data. Prometheus JMX Exporter is also a Java agent, which is capable of accessing the MBean server to access the data and transform that data into the Prometheus metric format. Prometheus then scrapes the metrics from the JMX Exporter's default metric storage path, which is **`/metrics`.** ## **JMX Exporter Setup on Kubernetes** Follow the steps given below to setup JMX exporter with java applications on Kubernetes. ### Step 1: Build Application Docker Image With JMX Agent JMX Exporter Java agent should be run with the application on the runtime. You can download the JMX exporter agent jar file from here -> [JMX Exporter Download](https://github.com/prometheus/jmx%5Fexporter/releases?ref=devopscube.com). So when you build the Docker image for you application, you should add the JMX exporter along with the image. Here is an example of a [Dockerfile](https://devopscube.com/create-dockerfile-using-docker-init/) that has both Java application jar and **jmx-agent** jar file. ``` FROM techiescamp/jre-17:1.0.0 ENV APP_NAME=jmx-java-app ENV JMX_PORT=5556 WORKDIR /app COPY /java-agent/*.jar /app/jmx-agent.jar COPY /java-app/*.jar /app/java.jar COPY config.yaml /app/ CMD java -javaagent:jmx-agent.jar=${JMX_PORT}:config.yaml -jar java.jar ``` I have already built the docker image and pushed it to Dockerhub. If you are learning ot testing JMX, you can use the following image directly. ``` techiescamp/jmx-pet-clinic-app:latest ``` ### Step 2: Create ConfigMap for the JMX Exporter We need to create a **ConfigMap** named `jmx-exporter-configmap.yaml` object for the JMX configs. In this file, we will provide information to filter the required metrics from the **MBean server**. This config avoids unnecessary metric collection limiting it to only the metrics we need. Create `jmx-exporter-configmap.yaml` ``` apiVersion: v1 kind: ConfigMap metadata: name: jmx-exporter-config namespace: monitoring data: config.yaml: |- lowercaseOutputName: true lowercaseOutputLabelNames: true whitelistObjectNames: ["java.lang:type=Memory", "java.lang:type=GarbageCollector,*"] ``` Here, you can see that I have mentioned that the **namespace value is monitoring**, this is because I have all my monitoring components in that particular namespace. If you want to use this same configuration, create a namespace with the same name before beginning the configuration. In the data section, we can define what kind of metrics the JMX Exporter has to collect from the **MBean server**. In this configuration I have given a small example to filter memory-related metrics of the application. To know more about the configuration, please visit the [official documentation](https://github.com/prometheus/jmx%5Fexporter?ref=devopscube.com). To deploy this configuration in the Kubernetes, use the following command. ``` kubectl apply -f jmx-exporter-configmap.yaml ``` To view the list configmaps in the monitoring namespace. ``` kubectl get configmaps -n monitoring ``` ### Step 3: Create a Deployment Manifest for the Application When creating the **Deployment** manifest, we have to expose the application and the metric ports, only then can we access the application and metrics over the Internet. Create a deployment YAML file `app-deployment.yaml.` ``` apiVersion: apps/v1 kind: Deployment metadata: name: jmx-java-app namespace: monitoring spec: replicas: 2 selector: matchLabels: app: jmx-java-app template: metadata: labels: app: jmx-java-app spec: containers: - name: jmx-java-app-container image: techiescamp/jmx-pet-clinic-app:latest ports: - containerPort: 8080 - containerPort: 5556 volumeMounts: - name: jmx-exporter-config-volume mountPath: /app/config.yaml subPath: config.yaml volumes: - name: jmx-exporter-config-volume configMap: name: jmx-exporter-config ``` Here, you can see I am exposing ports **8080** and **5556** outside the container. One important thing here is the **volumeMounts** section. The mountPath is uses the configmap as volumes. It overwrites the container default `/app/config.yaml` Now deploy the manifest. ``` kubectl apply -f app-deployment.yaml ``` To view the list of Deployments in the monitoring Namespace. ``` kubectl get deployments -n monitoring ``` To view the list of Pods in the monitoring Namespace. ``` kubectl get pods -n monitoring -o wide ``` For testing purposes, I have given two replicas, so we can see two Java application Pods running in the monitoring Namespace. ### Step 4: Create a Service for Application Create a Service manifest for the application `app-service.yaml` ``` apiVersion: v1 kind: Service metadata: name: jmx-java-app-nodeport namespace: monitoring spec: selector: app: jmx-java-app ports: - name: http protocol: TCP port: 8080 targetPort: 8080 nodePort: 30750 - name: jmx protocol: TCP port: 5556 targetPort: 5556 nodePort: 30850 type: NodePort ``` I want to access the application and the metrics over the internet so I am using the `spec.type: NodePort`, and defining the nodePort numbers such as **30750** for the application and **30850** for the metrics**.** To apply this configuration, use the following command. ``` kubectl apply -f app-service.yaml ``` To view the list of Services in the monitoring Namespace. ``` kubectl get svc -n monitoring ``` Now, let's try to access the application and metrics over the internet, for that, you need the **Public IP** of any one of the instances and the **port numbers.** The output of the **application** ![petclinic java app output](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/image-111-7.png) The output of the **metrics.** ![jmx exporter dashboard](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/image-112-7.png) ### Step 5: Add Scrape Config in Prometheus > **Note**: This configuration has to be done on the Prometheus server. The JMX Exporter is successfully exposing the metrics of the **Java application**. Now we add a job in the **Prometheus server configuration** file to scrape these metrics, and then only we can store them in **TSDB** or make queries. Find the Prometheus ConfigMap, in my setup, the file name is `config-map.yaml`. Open it with a text editor. ``` vim config-map.yaml ``` To view the list of configmaps in the monitoring namespace. ``` kubectl get configmaps -n monitoring ``` Add the following contents inside the configuration file, under the **scrape\_configs.** If you are using a label selector in the deployment manifest, replace all the occurrences of **`jmx-java-app`** with the respective label. ``` scrape_configs: - job_name: 'jmx-java-app' kubernetes_sd_configs: - role: pod namespaces: names: - monitoring relabel_configs: - source_labels: [__meta_kubernetes_pod_label_app] action: keep regex: 'jmx-java-app' - source_labels: [__meta_kubernetes_namespace] target_label: namespace - source_labels: [__meta_kubernetes_pod_name] target_label: pod_name - target_label: __address__ replacement: "jmx-java-app-nodeport:5556" ``` In this promtheus configuration, I am using the `kubernetes_sd_configs` [service discovery ](https://devopscube.com/service-discovery-explained/)method that automatically identifies the pods that belong to the j**`mx-java-app`** deployment using **`jmx-java-app`** label. So you don't need to manually provide the target details for scrapping the JMX metrics. To apply this configuration, use the following command. ``` kubectl apply -f config-map.yaml ``` It might take a few minutes to replicate the changes in the Prometheus dashboard. If you dont see the changes, then perform a deployment **rollout** using the following command. Change the **prometheus-deployment** to your actual Prometheus deployment name. ``` kubectl rollout restart deployment prometheus-deployment -n monitoring ``` ### Step 6: Validate JMX Metrics from Prometheus Dashboard You can validate the JMX targets from the Prometheus dashbaord. Under the **Targets** section, we can see the endpoint details, status, and other information as shown below. ![Prometheus dashboard with JMX targets](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/image-113-5.png) In the Graph section, we can make queries and get results. For example, the following dashboard shows**` jvm_memory_bytes_used`** metrics from the app. ![prometheus query for JMX metrics](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/image-114-3.png) ### Step 6: Grafana Dashboard We can **visualize** the JMX metrics in Grafana dashboards as per our requirements. If you have a [Grafana setup](https://devopscube.com/setup-grafana-kubernetes/) and added [Prometheus as a data source](https://devopscube.com/integrate-visualize-prometheus-grafana/), you can create dashboards using the [JMX metrics templates](https://grafana.com/grafana/dashboards/7727-jvm-overview/?ref=devopscube.com). You check out visualizing Promtheus metrics on Grafana blog to know more. ![Grafana dashboard for Promtheus JMX metrics](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/image-115-2.png) ## **Conclusion** In this blog we have covered steps to implement JMX Exporter on the **Kubernetes** cluster. You can make further configuration change that is suitable for your application. Also, in the exporter Configmap, you can add other filter settings for the JMX Exporter to collect other metrics that is required for the monitoring. Also, for setting for JMX exporter on [Linux VM based prometheus setup](https://devopscube.com/install-configure-prometheus-linux/), please [refer this guide.](https://devopscube.com/setup-prometheus-jmx-exporter/) If you face any errors or need clarification on the setup, drop a comment below.