Influxdb is a “time series” database for storing metrics. Temperatures, ram usage, cpu usage with time stamps. Telegraf is the client side agent that sends those metrics to the database in json format. Prometheus does pretty much the same thing but is a bit too bloated for my liking, so I went back to Influx.

My work environments use Prometheus and node-exporter and grafana. At home I use telegraf, influxdb and grafana (and Prometheus for other app specific metrics) but the biggest reason I went with telegraf and influxdb at home is because Prometheus scrapes data from the configured clients (pull), while telegraf sends the data on the configured interval to influxdb (push) and starting my homelab adventure I had 2 VMS in the cloud and 2 pis at home and having telegraf sending the data in to my pis rather than going out and scraping made it a lot easier for that remote setup. I had influxdb setup behind a reverse proxy and auth so telegraf was sending data over TLS and needed to authenticate to just the single endpoint. That is the major difference to me, but there are also subsets of other exporters and plugins and stuff to tailor data for each one depending on what you want.