grafana/pkg/services/ngalert/schedule/jitter_test.go
2024-04-29 21:52:15 -04:00

96 lines
3.7 KiB
Go

package schedule
import (
"testing"
"time"
"github.com/stretchr/testify/require"
ngmodels "github.com/grafana/grafana/pkg/services/ngalert/models"
)
func TestJitter(t *testing.T) {
gen := ngmodels.RuleGen
genWithInterval10to600 := gen.With(gen.WithIntervalBetween(10, 600))
t.Run("when strategy is JitterNever", func(t *testing.T) {
t.Run("offset is always zero", func(t *testing.T) {
rules := genWithInterval10to600.GenerateManyRef(100)
baseInterval := 10 * time.Second
for _, r := range rules {
offset := jitterOffsetInTicks(r, baseInterval, JitterNever)
require.Zero(t, offset, "unexpected offset, should be zero with jitter disabled; got %d", offset)
}
})
})
t.Run("when strategy is JitterByGroup", func(t *testing.T) {
t.Run("offset is stable for the same rule", func(t *testing.T) {
rule := genWithInterval10to600.GenerateRef()
baseInterval := 10 * time.Second
original := jitterOffsetInTicks(rule, baseInterval, JitterByGroup)
for i := 0; i < 100; i++ {
offset := jitterOffsetInTicks(rule, baseInterval, JitterByGroup)
require.Equal(t, original, offset, "jitterOffsetInTicks should return the same value for the same rule")
}
})
t.Run("offset is on the interval [0, interval/baseInterval)", func(t *testing.T) {
baseInterval := 10 * time.Second
rules := genWithInterval10to600.GenerateManyRef(1000)
for _, r := range rules {
offset := jitterOffsetInTicks(r, baseInterval, JitterByGroup)
require.GreaterOrEqual(t, offset, int64(0), "offset cannot be negative, got %d for rule with interval %d", offset, r.IntervalSeconds)
upperLimit := r.IntervalSeconds / int64(baseInterval.Seconds())
require.Less(t, offset, upperLimit, "offset cannot be equal to or greater than interval/baseInterval of %d", upperLimit)
}
})
t.Run("offset for any rule in the same group is always the same", func(t *testing.T) {
baseInterval := 10 * time.Second
group1 := ngmodels.AlertRuleGroupKey{}
group2 := ngmodels.AlertRuleGroupKey{}
rules1 := gen.With(gen.WithInterval(60*time.Second), gen.WithGroupKey(group1)).GenerateManyRef(1000)
rules2 := gen.With(gen.WithInterval(1*time.Hour), gen.WithGroupKey(group2)).GenerateManyRef(1000)
group1Offset := jitterOffsetInTicks(rules1[0], baseInterval, JitterByGroup)
for _, r := range rules1 {
offset := jitterOffsetInTicks(r, baseInterval, JitterByGroup)
require.Equal(t, group1Offset, offset)
}
group2Offset := jitterOffsetInTicks(rules2[0], baseInterval, JitterByGroup)
for _, r := range rules2 {
offset := jitterOffsetInTicks(r, baseInterval, JitterByGroup)
require.Equal(t, group2Offset, offset)
}
})
})
t.Run("when strategy is JitterByRule", func(t *testing.T) {
t.Run("offset is stable for the same rule", func(t *testing.T) {
rule := genWithInterval10to600.GenerateRef()
baseInterval := 10 * time.Second
original := jitterOffsetInTicks(rule, baseInterval, JitterByRule)
for i := 0; i < 100; i++ {
offset := jitterOffsetInTicks(rule, baseInterval, JitterByRule)
require.Equal(t, original, offset, "jitterOffsetInTicks should return the same value for the same rule")
}
})
t.Run("offset is on the interval [0, interval/baseInterval)", func(t *testing.T) {
baseInterval := 10 * time.Second
rules := genWithInterval10to600.GenerateManyRef(1000)
for _, r := range rules {
offset := jitterOffsetInTicks(r, baseInterval, JitterByRule)
require.GreaterOrEqual(t, offset, int64(0), "offset cannot be negative, got %d for rule with interval %d", offset, r.IntervalSeconds)
upperLimit := r.IntervalSeconds / int64(baseInterval.Seconds())
require.Less(t, offset, upperLimit, "offset cannot be equal to or greater than interval/baseInterval of %d", upperLimit)
}
})
})
}