How can I fetch a datapoint at certain time every day in Graphite?

Question

I have a series of data that increases by time and resets to zero at 18:00 every day. How can I make a Graphite plot that only contains datapoints at 17:59 in the last 30 days?

I have tried summarize(1d, max, false), but it by default bins data into buckets that are calculated by rounding to the nearest interval to current time. So I cannot specify the beginning time of each bucket to be 18:00.

Answer 1

I couldn't find anything that exactly matches what you want. There are functions like timeSlice and timeStack but they do not really fit.

An alternative is to use the graphite function nonNegativeDerivative. It ignores when counters are reset to zero and only shows counter increments.