prometheus/promql/functions_test.go
Brian Brazil 4c8173acac Use timestamp of a sample in deriv() to avoid FP issues (#2958)
With the squaring of the timestamp, we run into the
limitations of the 53bit mantissa for a 64bit float.

By subtracting away a timestamp of one of the samples (which is how the
intercept is used) we avoid this issue in practice as it's unlikely
that it is used over a very long time range.

Fixes #2674
2017-08-07 17:15:38 +01:00

110 lines
2.7 KiB
Go

// Copyright 2015 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 promql
import (
"context"
"testing"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/storage/local"
)
func BenchmarkHoltWinters4Week5Min(b *testing.B) {
input := `
clear
load 5m
http_requests{path="/foo"} 0+10x8064
eval instant at 4w holt_winters(http_requests[4w], 0.3, 0.3)
{path="/foo"} 80640
`
bench := NewBenchmark(b, input)
bench.Run()
}
func BenchmarkHoltWinters1Week5Min(b *testing.B) {
input := `
clear
load 5m
http_requests{path="/foo"} 0+10x2016
eval instant at 1w holt_winters(http_requests[1w], 0.3, 0.3)
{path="/foo"} 20160
`
bench := NewBenchmark(b, input)
bench.Run()
}
func BenchmarkHoltWinters1Day1Min(b *testing.B) {
input := `
clear
load 1m
http_requests{path="/foo"} 0+10x1440
eval instant at 1d holt_winters(http_requests[1d], 0.3, 0.3)
{path="/foo"} 14400
`
bench := NewBenchmark(b, input)
bench.Run()
}
func BenchmarkChanges1Day1Min(b *testing.B) {
input := `
clear
load 1m
http_requests{path="/foo"} 0+10x1440
eval instant at 1d changes(http_requests[1d])
{path="/foo"} 1440
`
bench := NewBenchmark(b, input)
bench.Run()
}
func TestDeriv(t *testing.T) {
// https://github.com/prometheus/prometheus/issues/2674#issuecomment-315439393
// This requires more precision than the usual test system offers,
// so we test it by hand.
storage, closer := local.NewTestStorage(t, 2)
defer closer.Close()
engine := NewEngine(storage, nil)
metric := model.Metric{model.MetricNameLabel: model.LabelValue("foo")}
storage.Append(&model.Sample{Metric: metric, Timestamp: 1493712816939, Value: 1.0})
storage.Append(&model.Sample{Metric: metric, Timestamp: 1493712846939, Value: 1.0})
storage.WaitForIndexing()
query, err := engine.NewInstantQuery("deriv(foo[30m])", 1493712846939)
if err != nil {
t.Fatalf("Error parsing query: %s", err)
}
result := query.Exec(context.Background())
if result.Err != nil {
t.Fatalf("Error running query: %s", result.Err)
}
vec, _ := result.Vector()
if vec.Len() != 1 {
t.Fatalf("Expected 1 result, got %d", vec.Len())
}
if vec[0].Value != 0.0 {
t.Fatalf("Expected 0.0 as value, got %f", vec[0].Value)
}
}