(You posted a blank image!) idelta(metric[period]) only gives the difference between the *last two points* in a range. Suppose the time period covered has the values (0, 0, 1, 1). The last two values are (1, 1) and idelta will give zero.
You say you're scraping data at 5 second intervals, and you're doing idelta(parcel[20s]). That looks at the last two points in a 20 second range Whether or not you see any blip on your graph depends on the graph resolution. Say you zoom out in your graphing frontend, such that the X axis only shows one point every 10 seconds. It's quite possible you'll skip over the increase. It might see: (0, 0, 0, 0) at time 0 (0, 0, 1, 1) at time 10 seconds (1, 1, 1, 1) at time 20 seconds and hence the idelta value for all three points will be zero. You should use delta not idelta, with a time window big enough to cover at least two data points. Note: since this is a counter, you should be using "increase", "irate" or "rate", not "(i)delta" - "rate" calculates the per-second increase, between the *first and last data points* in the time window (but skipping ranges where the counter resets, i.e. goes down). This is the normal one to use. - "irate" gives the rate between the *last two data points* in the time window. It suffers from the same problem you saw with idelta. - "increase" is "rate" multiplied by the time window - instead of "units per second" you get "units per 5 minutes" or whatever -- You received this message because you are subscribed to the Google Groups "Prometheus Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/prometheus-users/56b5340d-0945-4bd6-9e64-3a57c663727eo%40googlegroups.com.
