To monitor and find the top processes using Prometheus, you can follow these steps:

1. Install and Configure Node Exporter: Node Exporter collects various system-level metrics, including CPU, memory, disk, and network usage, and exposes them to Prometheus. Here's a basic outline of how to install Node Exporter:

   • Download the Node Exporter binary suitable for your operating system from the official Prometheus GitHub repository.

   • Extract the downloaded archive and move the node_exporter binary to a directory in your system path.

   • Run Node Exporter as a service or as a background process on each target machine you want to monitor.

Once Node Exporter is running, it will expose metrics at http://localhost:9100/metrics (by default), which Prometheus can scrape.

2. Configure Prometheus to Scrape Node Exporter Metrics: Modify the Prometheus configuration (prometheus.yml) to scrape metrics from Node Exporter. Add a job for Node Exporter with appropriate target configurations. Here's an example configuration snippet:

    scrape_configs:
      - job_name: 'node-exporter'
        static_configs:
          - targets: ['localhost:9100']
   

   Adjust the targets parameter as needed to point to the correct address and port where Node Exporter is running.

3. Query Top Processes in Prometheus: Once Prometheus is scraping metrics from Node Exporter, you can use PromQL queries to find top processes based on metrics such as CPU or memory usage. Here are some example PromQL queries:

   • To find the top processes by CPU usage:

       topk(5, process_cpu_seconds_total)
     

     This query returns the top 5 processes based on their cumulative CPU usage.

   • To find the top processes by memory usage:

       topk(5, process_resident_memory_bytes)
     

     This query returns the top 5 processes based on their resident memory usage.

You can adjust the number 5 in the topk() function to get more or fewer top processes as needed.

4. Visualization (Optional): You can visualize the results of these queries using Grafana or any other visualization tool that supports Prometheus data sources. Create dashboards or graphs to monitor the top processes' resource usage over time.

By following these steps, you can effectively monitor and find the top processes using Prometheus and Node Exporter. Adjust the queries and configurations based on your specific monitoring requirements and environment.