promql: return NaN from `irate()` if either of last two samples is NaN
Signed-off-by: Charles Korn <charles.korn@grafana.com>
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Signed-off-by: Charles Korn <charles.korn@grafana.com>
promql: fix double quoting in invalid label name error from `count_values`
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Signed-off-by: Charles Korn <charles.korn@grafana.com>
Signed-off-by: Charles Korn <charleskorn@users.noreply.github.com>
Co-authored-by: Björn Rabenstein <github@rabenste.in>
Fix duplicate output vector if delayed name removal is disabled
This error is emitted in cleanupMetricLabels, but is skipped if
enableDelayedNameRemoval is false.
This makes it consistent with label_replace
Signed-off-by: Joshua Hesketh <josh@nitrotech.org>
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Signed-off-by: Joshua Hesketh <josh@nitrotech.org>
Signed-off-by: Björn Rabenstein <github@rabenste.in>
Co-authored-by: Björn Rabenstein <github@rabenste.in>
If a rate (or increase) is calculated on native histograms, and there
is a counter reset between the 1st and 2nd histogram, we never have to
touch the 1st histogram, so it doesn't even matter if it has an
incompatible bucket layout. So we should not error out in that case.
This simply nulls out the 1st histogram in that case.
Signed-off-by: beorn7 <beorn@grafana.com>
promql: Add additional incompatible nhcb schemas tests for functions and comparison operators
* Add agg_over_time tests for nhcb with incompatible schemas
* Add more function and comparison operator tests
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Signed-off-by: Fiona Liao <fiona.liao@grafana.com>
Add test for `absent`, `absent_over_time` and `deriv` func with histograms
Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>
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Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>
promql: fix some aggregations for histograms
This PR fixes the behaviour of `topk`,`bottomk`, `limitk` and `limit_ratio` with histograms. The fixed behaviour are as follows:
- For `topk` and `bottomk` histograms are ignored and add info annotations added.
- For `limitk` and `limit_ratio` histograms are included in the results(if applicable).
Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>
promqltest: Complete the tests for info annotations
So far, we did not test for the _absence_ of an info annotation
(because many tests triggered info annotations, which we haven't taken
into account so far).
The test for info annotations was also missed for range queries.
This completes the tests for info annotations (and refactors the many
`if` statements into a somewhat more compact `switch` statement).
It fixes most tests to not emit an info annotation anymore. Or it
changes the `eval` to `eval_info` where we actually want to test for
the info annotation.
It also fixes a few spelling errors in comments.
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Signed-off-by: beorn7 <beorn@grafana.com>
Signed-off-by: Björn Rabenstein <github@rabenste.in>
Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>
This converts `TestNativeHistogram_SubOperator` to the promql testing framework. It also removes `TestNativeHistogram_Sum_Count_Add_AvgOperator`, which got converted earlier.
Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>
* tests(promql/testdata): add regression test for and-on
I'd like to use queries of the form "x and on() (vector(y)==1)" to be
able to include and exclude series for dashboards. This helps migration
to native histograms in dashboards by using a dashboard variable to
set "y" to either -1 or 1 to exclude or include the result.
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
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Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
* Fix issue where comparison operations with `bool` modifier and native histograms return histograms rather than 0 or 1
* Don't emit anything for comparisons between floats and histograms when `bool` modifier is used
* Don't emit anything for comparisons between floats and histograms when `bool` modifier is used between a vector and a scalar
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Signed-off-by: Charles Korn <charles.korn@grafana.com>
PromQL: Correct the behaviour of some operator and aggregators with Native Histograms
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Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>
promql: Fix stddev/stdvar when aggregating histograms, NaNs, and Infs
Native histograms are ignored when calculating stddev or stdvar.
However, for the first series of each group, a `groupedAggregation` is
always created. If the first series that was encountered is a histogram
then it acts as the equivalent of a 0 point.
This change creates the first `groupedAggregation` with the `seen` field set to `false` if the point is a
histogram, thus ignoring it like the rest of the aggregation function does. A new `groupedAggregation`
will then be created once an actual float value is encountered.
This commit also sets the `floatValue` field of the `groupedAggregation` to `NaN`, if the first
float value of a group is `NaN` or `±Inf`, so that the outcome is consistently `NaN` once those
values are in the mix.
(The added tests fail without this change).
Signed-off-by: Joshua Hesketh <josh@nitrotech.org>
Signed-off-by: beorn7 <beorn@grafana.com>
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Signed-off-by: Joshua Hesketh <josh@nitrotech.org>
Signed-off-by: beorn7 <beorn@grafana.com>
Co-authored-by: beorn7 <beorn@grafana.com>
promql: corrects binary operators functioning for mixed sample with histogram and float
For invalid pairings of sample types, an annotation is added now.
Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>
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Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>
promql: correctly handle unary negation of native histograms and add tests for multiplication and division of native histograms by negative scalars
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
The linear interpolation (assuming that observations are uniformly
distributed within a bucket) is a solid and simple assumption in lack
of any other information. However, the exponential bucketing used by
standard schemas of native histograms has been chosen to cover the
whole range of observations in a way that bucket populations are
spread out over buckets in a reasonably way for typical distributions
encountered in real-world scenarios.
This is the origin of the idea implemented here: If we divide a given
bucket into two (or more) smaller exponential buckets, we "most
naturally" expect that the samples in the original buckets will split
among those smaller buckets in a more or less uniform fashion. With
this assumption, we end up with an "exponential interpolation", which
therefore appears to be a better match for histograms with exponential
bucketing.
This commit leaves the linear interpolation in place for NHCB, but
changes the interpolation for exponential native histograms to
exponential. This affects `histogram_quantile` and
`histogram_fraction` (because the latter is more or less the inverse
of the former).
The zero bucket has to be treated specially because the assumption
above would lead to an "interpolation to zero" (the bucket density
approaches infinity around zero, and with the postulated uniform usage
of buckets, we would end up with an estimate of zero for all quantiles
ending up in the zero bucket). We simply fall back to linear
interpolation within the zero bucket.
At the same time, this commit makes the call to stick with the
assumption that the zero bucket only contains positive observations
for native histograms without negative buckets (and vice versa). (This
is an assumption relevant for interpolation. It is a mostly academic
point, as the zero bucket is supposed to be very small anyway.
However, in cases where it _is_ relevantly broad, the assumption helps
a lot in practice.)
This commit also updates and completes the documentation to match both
details about interpolation.
As a more high level note: The approach here attempts to strike a
balance between a more simplistic approach without any assumption, and
a more involved approach with more sophisticated assumptions. I will
shortly describe both for reference:
The "zero assumption" approach would be to not interpolate at all, but
_always_ return the harmonic mean of the bucket boundaries of the
bucket the quantile ends up in. This has the advantage of minimizing
the maximum possible relative error of the quantile estimation.
(Depending on the exact definition of the relative error of an
estimation, there is also an argument to return the arithmetic mean of
the bucket boundaries.) While limiting the maximum possible relative
error is a good property, this approach would throw away the
information if a quantile is closer to the upper or lower end of the
population within a bucket. This can be valuable trending information
in a dashboard. With any kind of interpolation, the maximum possible
error of a quantile estimation increases to the full width of a bucket
(i.e. it more than doubles for the harmonic mean approach, and
precisely doubles for the arithmetic mean approach). However, in
return the _expectation value_ of the error decreases. The increase of
the theoretical maximum only has practical relevance for pathologic
distributions. For example, if there are thousand observations within
a bucket, they could _all_ be at the upper bound of the bucket. If the
quantile calculation picks the 1st observation in the bucket as the
relevant one, an interpolation will yield a value close to the lower
bucket boundary, while the true quantile value is close to the upper
boundary.
The "fancy interpolation" approach would be one that analyses the
_actual_ distribution of samples in the histogram. A lot of statistics
could be applied based on the information we have available in the
histogram. This would include the population of neighboring (or even
all) buckets in the histogram. In general, the resolution of a native
histogram should be quite high, and therefore, those "fancy"
approaches would increase the computational cost quite a bit with very
little practical benefits (i.e. just tiny corrections of the estimated
quantile value). The results are also much harder to reason with.
Signed-off-by: beorn7 <beorn@grafana.com>
