All commands have to be executed in the prometheus_workshop directory.
node_exporter is a program that collects hardware and OS metrics for Prometheus.
Start node_exporter in a terminal:
node_exporter
Go to http://localhost:9100/ and check the results.
Start Prometheus in another terminal:
prometheus --config.file=conf/getting_started/prometheus.yml --storage.tsdb.path=./data/prometheus
The configuration file tells Prometheus to scrape metrics from 3 targets:
- Prometheus itself.
- node_exporter (running on localhost).
- An fake instance that can't be reached.
Go to http://localhost:9090/ to access the Prometheus web UI.
Visit the Targets and check that the 3 targets are listed, node_exporter and Prometheus should be UP.
You can click on the Prometheus target link to view the exposed metrics.
Go to the Graph and execute the following query:
up
The up metric isn't found in the metrics exposed by the endpoints, it is
instead added by Prometheus itself everytime it scrapes the target.
There are other metrics like up which are generated by Prometheus. To find them, execute the following query:
{job="unreachable"}
It should return something similar to:
scrape_duration_seconds{instance="127.0.0.1:80",job="unreachable"} 0.003171684
scrape_samples_post_metric_relabeling{instance="127.0.0.1:80",job="unreachable"} 0
scrape_samples_scraped{instance="127.0.0.1:80",job="unreachable"} 0
scrape_series_added{{instance="127.0.0.1:80",job="unreachable"} 0
up{instance="127.0.0.1:80",job="unreachable"} 0
You can check other metrics. For instance:
process_resident_memory_bytes
Note that we got 2 results here. Switch between Console & Graph and see what differs.