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// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package raft
import (
"testing"
"time"
"github.com/stretchr/testify/require"
)
func TestSaturationMetric(t *testing.T) {
t.Run("without smoothing", func(t *testing.T) {
sat := newSaturationMetric([]string{"metric"}, 100*time.Millisecond)
now := sat.lastReport
sat.nowFn = func() time.Time { return now }
var reported float32
sat.reportFn = func(val float32) { reported = val }
sat.sleeping()
// First window: 50ms sleeping + 75ms working.
now = now.Add(50 * time.Millisecond)
sat.working()
now = now.Add(75 * time.Millisecond)
sat.sleeping()
// Should be 60% saturation.
require.Equal(t, float32(0.6), reported)
// Second window: 90ms sleeping + 10ms working.
now = now.Add(90 * time.Millisecond)
sat.working()
now = now.Add(10 * time.Millisecond)
sat.sleeping()
// Should be 10% saturation.
require.Equal(t, float32(0.1), reported)
// Third window: 100ms sleeping + 0ms working.
now = now.Add(100 * time.Millisecond)
sat.working()
// Should be 0% saturation.
require.Equal(t, float32(0), reported)
})
}
func TestSaturationMetric_IncorrectUsage(t *testing.T) {
t.Run("calling sleeping() consecutively", func(t *testing.T) {
sat := newSaturationMetric([]string{"metric"}, 50*time.Millisecond)
now := sat.lastReport
sat.nowFn = func() time.Time { return now }
var reported float32
sat.reportFn = func(v float32) { reported = v }
// Calling sleeping() consecutively should reset sleepBegan without recording
// a sample, such that we "lose" time rather than recording nonsense data.
//
// 0 | sleeping() |
// => Sleeping (10ms)
// +10ms | working() |
// => Working (10ms)
// +20ms | sleeping() |
// => [!] LOST [!] (10ms)
// +30ms | sleeping() |
// => Sleeping (10ms)
// +40ms | working() |
// => Working (10ms)
// +50ms | sleeping() |
//
// Total reportable time: 40ms. Saturation: 50%.
sat.sleeping()
now = now.Add(10 * time.Millisecond)
sat.working()
now = now.Add(10 * time.Millisecond)
sat.sleeping()
now = now.Add(10 * time.Millisecond)
sat.sleeping()
now = now.Add(10 * time.Millisecond)
sat.working()
now = now.Add(10 * time.Millisecond)
sat.sleeping()
require.Equal(t, float32(0.5), reported)
})
t.Run("calling working() consecutively", func(t *testing.T) {
sat := newSaturationMetric([]string{"metric"}, 30*time.Millisecond)
now := sat.lastReport
sat.nowFn = func() time.Time { return now }
var reported float32
sat.reportFn = func(v float32) { reported = v }
// Calling working() consecutively should reset workBegan without recording
// a sample, such that we "lose" time rather than recording nonsense data.
//
// 0 | sleeping() |
// => Sleeping (10ms)
// +10ms | working() |
// => [!] LOST [!] (10ms)
// +20ms | working() |
// => Working (10ms)
// +30ms | sleeping() |
//
// Total reportable time: 20ms. Saturation: 50%.
sat.sleeping()
now = now.Add(10 * time.Millisecond)
sat.working()
now = now.Add(10 * time.Millisecond)
sat.working()
now = now.Add(10 * time.Millisecond)
sat.sleeping()
require.Equal(t, float32(0.5), reported)
})
t.Run("calling working() first", func(t *testing.T) {
sat := newSaturationMetric([]string{"metric"}, 10*time.Millisecond)
now := sat.lastReport
sat.nowFn = func() time.Time { return now }
var reported float32
sat.reportFn = func(v float32) { reported = v }
// Time from start until working() is treated as lost.
sat.working()
require.Equal(t, float32(0), reported)
sat.sleeping()
now = now.Add(5 * time.Millisecond)
sat.working()
now = now.Add(5 * time.Millisecond)
sat.sleeping()
require.Equal(t, float32(0.5), reported)
})
}
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