PromQL rate() vs increase()
I keep mixing up rate() and increase() in PromQL, so this is a short note for future reference. Both functions are normally used with counters: metrics that only go up, except when the process restarts and the counter resets. The quick difference: rate() answers: how fast is it increasing? increase() answers: how much did it increase? rate() rate() gives the average per-second increase over a time range. rate(http_requests_total[5m]) If the counter moved from around 280 to 700, the increase is 420. In this example the sampled time difference is 270 seconds, so: ...