app/vmselect/promql: an attempt to improve heuristics for dropping trailing data points in time series

Now trailing data points are additionally dropped for time series with a single raw sample

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/748
This commit is contained in:
Aliaksandr Valialkin 2020-10-17 10:39:35 +03:00
parent 01987f8c77
commit 28353e48ca

View File

@ -519,9 +519,10 @@ func (rc *rollupConfig) doInternal(dstValues []float64, tsm *timeseriesMap, valu
}
rfa.values = values[i:j]
rfa.timestamps = timestamps[i:j]
if j == len(timestamps) && i < j && tEnd-timestamps[j-1] > stalenessInterval {
// Do not take into account the last data point in time series if the distance between this data point
// and tEnd exceeds stalenessInterval.
if j == len(timestamps) && j > 0 && (tEnd-timestamps[j-1] > stalenessInterval || i == j && len(timestamps) == 1) {
// Drop trailing data points in the following cases:
// - if the distance between the last raw sample and tEnd exceeds stalenessInterval
// - if time series contains only a single raw sample
// This should prevent from double counting when a label changes in time series (for instance,
// during new deployment in K8S). See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/748
rfa.prevValue = nan