Hector Martin

is there any tool for collecting, storing and graphing approximately 3 samples per second that's more pretty (and interactive) than rrdtool but less enormous than something like grafana please don't say "echo, csv and excel". i know that will work fine, just... ugh

Prometheus (pull-based) or Graphite (push-based)? They both IIRC come with their own built-in explorer and graph renderer, that's not as pretty as grafana but definitely good enough.

This. Grafana is just a frontend, but Prometheus itself is a single Go binary and has a usable web UI with graphing.

FWIW all you need to put stuff into Prometheus is serve a trivial text format on an HTTP endpoint.

(ignore the client libraries, they're all overkill, just roll your own in like 10 lines of code)

that's actually a problem for me because the sensor node is some piece of junk like an esp8266 and it's behind a NAT i don't control

FWIW I have some code to serve prom metrics directly from an esp8266 (that is actually reliable).