otel-collector/exporter/metadataexporter/vt_test.go

package metadataexporter

import (
	"fmt"
	"math/rand"
	"testing"
	"time"
)

func BenchmarkValueTracker_RealisticLoad(b *testing.B) {
	const (
		numSpans         = 100_000
		batchSize        = 50_000
		totalKeys        = 1_000
		highCardinalKeys = 200 // 20% of keys
		normalValuePool  = 100
		normalUniqueVals = 30
	)

	tracker := NewValueTracker(1000, 10000, 45*time.Minute)
	defer tracker.Close()

	r := rand.New(rand.NewSource(time.Now().UnixNano()))

	keys := make([]string, totalKeys)
	highCardinalKeyMap := make(map[string]bool)

	for i := 0; i < highCardinalKeys; i++ {
		keys[i] = fmt.Sprintf("high-card-key-%d", i)
		highCardinalKeyMap[keys[i]] = true
	}

	for i := highCardinalKeys; i < totalKeys; i++ {
		keys[i] = fmt.Sprintf("key-%d", i)
	}

	valuePool := make(map[string][]string)
	for _, key := range keys {
		if !highCardinalKeyMap[key] {
			values := make([]string, normalValuePool)
			for i := 0; i < normalUniqueVals; i++ {
				values[i] = fmt.Sprintf("unique-value-%s-%d", key, i)
			}
			for i := normalUniqueVals; i < normalValuePool; i++ {
				values[i] = values[r.Intn(normalUniqueVals)]
			}
			valuePool[key] = values
		}
	}

	uniqueValueCounter := make(map[string]int)
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		for j := 0; j < numSpans; j += batchSize {
			batchSize := min(batchSize, numSpans-j)

			for k := 0; k < batchSize; k++ {
				numAttrs := 10 + r.Intn(41)
				for a := 0; a < numAttrs; a++ {
					key := keys[r.Intn(len(keys))]
					var value string

					if highCardinalKeyMap[key] {
						uniqueValueCounter[key]++
						value = fmt.Sprintf("unique-value-%s-%d", key, uniqueValueCounter[key])
					} else {
						values := valuePool[key]
						value = values[r.Intn(len(values))]
					}

					tracker.AddValue(key, value)
				}
			}

			for k := 0; k < 10; k++ {
				key := keys[r.Intn(len(keys))]
				tracker.GetUniqueValueCount(key)
			}
		}
	}
}

func BenchmarkValueTracker_HighCardinality(b *testing.B) {
	tracker := NewValueTracker(1000, 100000, 45*time.Minute)
	defer tracker.Close()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		// Add 100K unique values to a single key
		key := "high-card-key"
		for j := 0; j < 100000; j++ {
			tracker.AddValue(key, fmt.Sprintf("unique-value-%d", j))
		}
	}
}