Port 9090: Prometheus UI + API

Prometheus UI + API

Prometheus — TSDB for metrics. Port 9090 — web UI + HTTP API for PromQL queries. Standard monitoring stack component (with Grafana + Alertmanager).

Prometheus without auth = anonymous access to every metric (can leak sensitive info like DB query duration, user IDs in histogram labels). Basic auth via nginx reverse proxy or OAuth2 proxy.

Check port online →

Enterno.io Ping + Port checker tests TCP reachability of any port from our server in Moscow.

Prometheus is an open-source monitoring and alerting toolkit widely used for recording real-time metrics in a time-series database (TSDB). It provides a robust set of features that allow users to monitor their applications and infrastructure effectively. Port 9090 (TCP) is the default port for accessing the Prometheus user interface (UI) and its HTTP API, which allows for querying metrics using PromQL (Prometheus Query Language).

The Prometheus UI provides a web interface where users can visualize metrics, create graphs, and execute queries. It serves as a central hub for interacting with the metrics collected from various targets. The API on port 9090 enables programmatic access to these metrics, allowing users to integrate Prometheus with other tools and services.

Some key features of Prometheus that utilize port 9090 include:

• Data Visualization: Users can create dashboards to visualize metrics over time, identify trends, and spot anomalies.
• Alerting: Prometheus can trigger alerts based on specific conditions defined in alert rules, which can be integrated with Alertmanager.
• Service Discovery: Prometheus supports various service discovery mechanisms, allowing it to automatically discover and scrape metrics from targets.

Understanding how to leverage port 9090 effectively is essential for optimizing the monitoring of your applications and infrastructure.

To effectively utilize port 9090 for monitoring with Prometheus, it’s important to understand how to configure and interact with the service. Below are practical examples demonstrating how to set up and query metrics using Prometheus.

1. Configuring Prometheus to Scrape Metrics:

In your prometheus.yml configuration file, you can define your scrape targets. Here’s an example configuration:

global:
  scrape_interval: 15s  # Set the scrape interval to every 15 seconds

scrape_configs:
  - job_name: 'my_application'
    static_configs:
      - targets: ['localhost:8080']  # Replace with your application’s endpoint

This configuration tells Prometheus to scrape metrics from your application running on localhost:8080 every 15 seconds.

2. Accessing the Prometheus UI:

Once Prometheus is running, you can access the UI by navigating to http://localhost:9090 in your web browser. Here, you can execute PromQL queries to retrieve metrics.

3. Example PromQL Queries:

Here are some example queries you can run in the Prometheus UI:

• up: This will return the status of all monitored targets. A value of 1 indicates the target is up, while 0 indicates it is down.
• http_requests_total{status="200"}: This query retrieves the total number of HTTP requests that returned a 200 status code.
• rate(cpu_usage[5m]): This calculates the per-second average CPU usage over the last 5 minutes.

These examples illustrate how to configure Prometheus and utilize port 9090 for monitoring and querying metrics effectively.

When using port 9090 for Prometheus, it is crucial to address security considerations to protect sensitive data and ensure the integrity of your monitoring setup. Here are some key aspects to consider:

1. Network Access Control:

Limit access to port 9090 by configuring your firewall or security groups. Only allow trusted IP addresses or networks to connect to this port. This prevents unauthorized access to your Prometheus UI and API.

2. Authentication and Authorization:

By default, Prometheus does not provide built-in authentication. It’s recommended to use a reverse proxy (such as Nginx or Apache) in front of Prometheus to enforce authentication. You can set up basic authentication or use OAuth2 for more robust security.

3. Encrypted Communications:

To protect data in transit, configure HTTPS for the Prometheus UI and API. This can be achieved through your reverse proxy setup. Ensure that you use valid SSL certificates to avoid security warnings.

4. Regular Updates:

Keep your Prometheus installation up to date. Regularly check for updates and security patches to mitigate vulnerabilities. The Prometheus team actively maintains the software, so staying current is essential for security.

5. Monitoring and Logging:

Implement logging and monitoring for access to port 9090. Use tools like Fail2Ban to monitor for suspicious activity and automatically block IPs that exhibit malicious behavior.

By addressing these security considerations, you can significantly reduce the risk associated with using port 9090 for Prometheus and ensure a secure monitoring environment.