In this section, we will explore how to use Prometheus and Grafana to monitor and visualize metrics from your Spring Boot application. Prometheus is an open-source monitoring and alerting toolkit, while Grafana is an open-source platform for monitoring and observability that allows you to query, visualize, alert on, and understand your metrics.

• Time-Series Database: Prometheus stores all data as time series, i.e., streams of timestamped values belonging to the same metric and the same set of labeled dimensions.
• Pull-Based Model: Prometheus scrapes (pulls) metrics from instrumented jobs.
• PromQL: Prometheus Query Language used to query the time-series data.

• Dashboards: Grafana allows you to create dashboards with panels, each representing specific metrics.
• Data Sources: Grafana supports various data sources, including Prometheus.
• Alerting: Grafana can send alerts based on the data it visualizes.

Download and install Prometheus from the official website.

Create a prometheus.yml configuration file:

Run Prometheus using the following command:

Add the following dependencies to your pom.xml:

Configure your application.properties:

Ensure that the /actuator/prometheus endpoint is exposed. This is typically done by default when you include the spring-boot-starter-actuator dependency.

Download and install Grafana from the official website.

1. Open Grafana in your browser (default is http://localhost:3000).
2. Log in with the default credentials (admin/admin).
3. Navigate to Configuration > Data Sources.
4. Add a new data source and select Prometheus.
5. Set the URL to http://localhost:9090 (default Prometheus server URL).
6. Click Save & Test to verify the connection.

1. Navigate to Create > Dashboard.
2. Add a new panel.
3. Select Prometheus as the data source.
4. Use PromQL to query metrics, e.g., http_requests_total.
5. Customize the visualization and save the dashboard.

• Total HTTP Requests: http_requests_total
• Request Duration: histogram_quantile(0.95, sum(rate(http_request_duration_seconds_bucket[5m])) by (le))

1. Query: http_requests_total
2. Visualization: Select Graph.
3. Panel Title: "Total HTTP Requests".
4. Save: Save the panel and add it to your dashboard.

1. Setup: Install Prometheus and Grafana as described.
2. Instrument: Add the necessary dependencies and configurations to your Spring Boot application.
3. Run: Start Prometheus and Grafana.
4. Create Dashboard: Create a Grafana dashboard to visualize metrics such as total HTTP requests and request duration.

1. Prometheus Configuration: Ensure prometheus.yml is correctly configured.
2. Spring Boot Configuration: Ensure application.properties is correctly configured.
3. Grafana Data Source: Verify the Prometheus data source is correctly added.
4. Dashboard: Create panels with appropriate PromQL queries.

• Incorrect Prometheus Configuration: Ensure the prometheus.yml file is correctly configured with the correct target.
• Missing Dependencies: Ensure all necessary dependencies are added to your Spring Boot project.
• Data Source Issues: Verify the Prometheus data source URL in Grafana is correct.
• Query Errors: Double-check PromQL queries for syntax errors.

In this section, we covered how to set up Prometheus and Grafana to monitor a Spring Boot application. We learned how to install and configure Prometheus, instrument a Spring Boot application to expose metrics, and create Grafana dashboards to visualize these metrics. This setup is crucial for maintaining the health and performance of your applications in a production environment.