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54 commits

Author SHA1 Message Date
Aliaksandr Valialkin
d261fa2885 app/vmselect/promql: add deriv_fast function for calculating fast derivative
`deriv_fast` calculates derivative based on the first and the last point on the interval
instead of calculating linear regression based on all the data points on the interval.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/73
2019-06-21 23:05:39 +03:00
Aliaksandr Valialkin
5b47c00910 app/vmselect/promql: use linear regression in deriv func like Prometheus does
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/73
2019-06-21 22:59:46 +03:00
Aliaksandr Valialkin
9e1119dab8 app/vmselect/promql: ajdust data model to the model used in Prometheus
Do not take into account data points on the range `[timestamp .. timestamp+step)`
when calculating value on the given `timestamp`.
Use only data points from the past when performing these calculations like Prometheus does.

This should reduce discrepancies between results returned by VictoriaMetrics
and results returned by Prometheus.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/72
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/71
2019-06-21 21:54:48 +03:00
Aliaksandr Valialkin
1836c415e6 all: open-sourcing single-node version 2019-05-23 00:18:06 +03:00