prometheus/tsdb/tsdbutil/histogram.go
beorn7 aa82fe198f tsdb: Fix histogram validation
So far, `ValidateHistogram` would not detect if the count did not
include the count in the zero bucket. This commit fixes the problem
and updates all the tests that have been undetected offenders so far.

Note that this problem would only ever create false negatives, so we
never falsely rejected to store a histogram because of it.

On the other hand, `ValidateFloatHistogram` has been to strict with
the count being at least as large as the sum of the counts in all the
buckets. Float precision issues could create false positives here, see
products of PromQL evaluations, it's actually quite hard to put an
upper limit no the floating point imprecision. Users could produce the
weirdest expressions, maxing out float precision problems. Therefore,
this commit simply removes that particular check from
`ValidateFloatHistogram`.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-08-22 23:04:01 +02:00

121 lines
3.4 KiB
Go

// Copyright 2023 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tsdbutil
import (
"math/rand"
"github.com/prometheus/prometheus/model/histogram"
)
func GenerateTestHistograms(n int) (r []*histogram.Histogram) {
for i := 0; i < n; i++ {
h := GenerateTestHistogram(i)
if i > 0 {
h.CounterResetHint = histogram.NotCounterReset
}
r = append(r, h)
}
return r
}
// GenerateTestHistogram but it is up to the user to set any known counter reset hint.
func GenerateTestHistogram(i int) *histogram.Histogram {
return &histogram.Histogram{
Count: 12 + uint64(i*9),
ZeroCount: 2 + uint64(i),
ZeroThreshold: 0.001,
Sum: 18.4 * float64(i+1),
Schema: 1,
PositiveSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
PositiveBuckets: []int64{int64(i + 1), 1, -1, 0},
NegativeSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
NegativeBuckets: []int64{int64(i + 1), 1, -1, 0},
}
}
func GenerateTestGaugeHistograms(n int) (r []*histogram.Histogram) {
for x := 0; x < n; x++ {
r = append(r, GenerateTestGaugeHistogram(rand.Intn(n)))
}
return r
}
func GenerateTestGaugeHistogram(i int) *histogram.Histogram {
h := GenerateTestHistogram(i)
h.CounterResetHint = histogram.GaugeType
return h
}
func GenerateTestFloatHistograms(n int) (r []*histogram.FloatHistogram) {
for i := 0; i < n; i++ {
h := GenerateTestFloatHistogram(i)
if i > 0 {
h.CounterResetHint = histogram.NotCounterReset
}
r = append(r, h)
}
return r
}
// GenerateTestFloatHistogram but it is up to the user to set any known counter reset hint.
func GenerateTestFloatHistogram(i int) *histogram.FloatHistogram {
return &histogram.FloatHistogram{
Count: 12 + float64(i*9),
ZeroCount: 2 + float64(i),
ZeroThreshold: 0.001,
Sum: 18.4 * float64(i+1),
Schema: 1,
PositiveSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
PositiveBuckets: []float64{float64(i + 1), float64(i + 2), float64(i + 1), float64(i + 1)},
NegativeSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
NegativeBuckets: []float64{float64(i + 1), float64(i + 2), float64(i + 1), float64(i + 1)},
}
}
func GenerateTestGaugeFloatHistograms(n int) (r []*histogram.FloatHistogram) {
for x := 0; x < n; x++ {
r = append(r, GenerateTestGaugeFloatHistogram(rand.Intn(n)))
}
return r
}
func GenerateTestGaugeFloatHistogram(i int) *histogram.FloatHistogram {
h := GenerateTestFloatHistogram(i)
h.CounterResetHint = histogram.GaugeType
return h
}
func SetHistogramNotCounterReset(h *histogram.Histogram) *histogram.Histogram {
h.CounterResetHint = histogram.NotCounterReset
return h
}
func SetFloatHistogramNotCounterReset(h *histogram.FloatHistogram) *histogram.FloatHistogram {
h.CounterResetHint = histogram.NotCounterReset
return h
}