> ## Documentation Index > Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt > Use this file to discover all available pages before exploring further. # Prometheus Configuration > This guide explains how to configure a Prometheus server to scrape metrics from one or multiple nodes. This guide explains how to configure a Prometheus server to scrape metrics from one or multiple nodes. After installing Prometheus and setting up your nodes with Node Exporters to expose metrics, you must explicitly configure Prometheus to discover and scrape these targets using its pull-based model. The configuration is maintained in the prometheus.yaml file, typically found in the /etc/prometheus directory. Below is a basic Prometheus configuration example: ```yaml theme={null} # my global config global: scrape_configs: - job_name: "prometheus" static_configs: - targets: ["localhost:9090"] ``` In this configuration: * The **global** section defines default parameters, which can be inherited or overridden by other sections. * The **scrape\_configs** section specifies the target endpoints for scraping metrics. *** ## Detailed Scrape Configuration Prometheus uses the **scrape\_configs** block to identify targets for metric collection. In this enhanced example, additional parameters—such as `scrape_interval`, `scrape_timeout`, and `sample_limit`—allow you to fine-tune the scraper’s behavior. ```yaml theme={null} global: scrape_interval: 1m scrape_timeout: 10s scrape_configs: - job_name: 'node' scrape_interval: 15s scrape_timeout: 5s sample_limit: 1000 static_configs: - targets: ['172.16.12.1:9090'] # Configuration related to AlertManager alerting: # Rule files specifying where rules are read from rule_files: # Remote read/write settings remote_read: remote_write: # Storage-related settings storage: ``` Key points in this configuration: * Global defaults specify a 1-minute scrape interval and a 10-second timeout. * The **node** job overrides these defaults, setting a 15-second interval and a 5-second timeout. * The **static\_configs** block clearly indicates the target IP and port for scraping metrics. Additional configuration blocks like **alerting**, **rule\_files**, **remote\_read**, **remote\_write**, and **storage** are available for extended use cases. *** ## Customizing Job Configurations When adding a new job under **scrape\_configs**, you must specify details such as the job name, scrape interval, timeout, scheme (HTTP/HTTPS), and the metrics path. By default, Prometheus scrapes metrics from the `/metrics` endpoint; however, customization is possible if your target uses a different endpoint. For instance, the following configuration demonstrates how to scrape two targets over HTTPS using a custom metrics path: ```yaml theme={null} scrape_configs: - job_name: 'nodes' scrape_interval: 30s scrape_timeout: 3s scheme: https metrics_path: /stats/metrics static_configs: - targets: ['10.231.1.2:9090', '192.168.43.9:9090'] ``` This configuration shows: * A job called **nodes** that scrapes every 30 seconds. * A 3-second scrape timeout. * Usage of HTTPS for securing the connection. * Changing the default metrics path from `/metrics` to `/stats/metrics`. * Two specified target nodes with their respective IP addresses and ports. The section below summarizes common adjustable options in the **scrape\_configs**: ```yaml theme={null} scrape_configs: # Frequency to scrape targets from this job. [ scrape_interval: | default = ] # Per-scrape timeout for this job. [ scrape_timeout: | default = ] # HTTP resource path for fetching metrics. [ metrics_path: | default = /metrics ] # Protocol scheme used for requests. [ scheme: | default = http ] # Sets the 'Authorization' header for each scrape request. # Note: 'password' and 'password_file' are mutually exclusive. basic_auth: [ username: ] [ password: ] [ password_file: ] ``` These options allow you to tailor the timing, endpoint, and authentication settings for each job as needed. *** ## Updating the Prometheus Configuration After modifying the prometheus.yaml file, Prometheus does not automatically reload changes. You must restart the Prometheus process. If running Prometheus manually (e.g., using `./prometheus`), you can simply press Ctrl+C and restart the process. For Prometheus running under systemd, use one of the following methods: ```bash theme={null} $ ctrl+c -> ./prometheus $ kill -HUP ``` Or restart via systemd with: ```bash theme={null} sudo systemctl restart prometheus ``` Consider an updated prometheus.yaml configuration that adds a new job for scraping a Node Exporter on a specific Linux machine: ```yaml theme={null} # my global config global: scrape_interval: 15s # Scrape every 15 seconds (default is 1 minute). evaluation_interval: 15s # Evaluate rules every 15 seconds (default is 1 minute). # scramble_timeout uses the global default (10s). # Alertmanager configuration alerting: alertmanagers: - static_configs: - targets: - alertmanager:9093 # Load rules periodically based on the global evaluation interval. rule_files: # - "first_rules.yml" # - "second_rules.yml" # Scrape configuration: # Prometheus scrapes itself via the "prometheus" job. scrape_configs: - job_name: "prometheus" # metrics_path defaults to `/metrics` # scheme defaults to `http`. static_configs: - targets: ["localhost:9090"] - job_name: "node" static_configs: - targets: ["192.168.1.168:9100"] ``` In this updated configuration: * The **prometheus** job continues to scrape Prometheus itself. * A new **node** job is added to scrape a Linux machine running Node Exporter on IP 192.168.1.168 at port 9100. After updating the configuration, restart the Prometheus service to apply the changes: ```bash theme={null} user1 in ~/prometheus-2.37.2.linux-amd64 ➜ sudo vi /etc/prometheus/prometheus.yml user1 in ~/prometheus-2.37.2.linux-amd64 took 1m52s ➜ sudo systemctl restart prometheus ``` Remember to save your changes to prometheus.yaml and restart Prometheus to apply the new configuration. *** ## Verifying the Configuration After restarting Prometheus, open the Prometheus web UI and navigate to the “Status” -> “Targets” page. Here you can inspect all configured targets and their scrape status. Both the Prometheus target and the new node target should display an "UP" status for successful metric collection. ![The image shows a Prometheus monitoring dashboard displaying two active targets, "node" and "prometheus," both in an "UP" state with their respective endpoints and scrape details.](https://kodekloud.com/kk-media/image/upload/v1752880533/notes-assets/images/Kubernetes-and-Cloud-Native-Associate-KCNA-Prometheus-Configuration/frame_480.jpg) You can further verify the configuration by executing queries such as: ```promql theme={null} up{instance="192.168.1.100",job="node"} up{instance="localhost:9090",job="prometheus"} ``` A returned value of 1 confirms that the instances are active and functional. *** This article demonstrated how to modify your Prometheus configuration file to add new scrape targets and adjust parameters such as scrape interval, timeout, and metrics path. By following these steps, Prometheus can successfully collect metrics from both itself and external nodes running Node Exporters.