Adjustment results into discrepancy between Prometheus and VM on time windows
smaller than scrape interval.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The fix will always return zero if received set of items consists of one
element only, which also means no deviation.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The change affects `count/stddev/stdvar_over_time` funcs and makes
them to return NaN instead of zero when there is no datapoints
in a time window.
This is needed for improving compatibility with Prometheus.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The removed fast path optimisations weren't consistent with
`quantile` function behavior and results into discrepancy.
Specifically, results didn't match in cases when:
* 0 < phi > 1;
* values contain only one element.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmselect: `quantile` func compatiblity with Prometheus
The `quantile` func was previously calculated by https://github.com/valyala/histogram
package. The result of such calculation was always the closest real value to
requested quantile. While in Prometheus implementation interpolation is used.
Such difference may result into discrepancy in output between Prometheus and
VictoriaMetrics.
This commit adds a Prometheus-like `quantile` function. It also used by other
functions which depend on it, such as `quantiles`, `quantile_over_time`, `median` etc.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1625
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmselect: `quantile` review fixes
* quantile functions were split into multiple to provide
different API for already sorted data;
* float64sPool is used for reducing allocations. Items in pool may have
different sizes, but defining a new pool was complicates due to name collisions;
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmselect: make sorting for query result similar to Prometheus
Updated sorting allows to get the order of series in result similar or equal
to what Prometheus returns.
The change is needed for compatibility reasons.
* Update app/vmselect/promql/exec_test.go
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
`omitempty` tag resulted into skipping this param on marshaling,
which was used as a checksum for groups configuration. Since on
config reload checksums are compared before applying changes,
any change to `interval` only didn't trigger config reload.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1641
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The commit contains the following changes:
- Show vmui when requesting /graph page in order to be compatible with Prometheus datasource in Grafana.
- Properly encode query args at vmui url.
- Set the number of points on the graph to the number of horizontal pixels divided by 2. Previously it was hardcoded to 30.
- Do not save server url to persistent storage at browser, since it should be always obtained from the url.
- Run `make vmui-update` for updating vmui embedded into VictoriaMetrics.
* feat: change url params for compatible prometheus
* style: add comment for TimeParams
* fix: change get default server for single version
* fix: change function for get query string value
* vmalert: add flag to limit the max value for auto-resovle duration for alerts
The new flag `rule.maxResolveDuration` suppose to limit max value for
alert.End param, which is used by notifiers like Alertmanager for alerts auto resolve.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1586
