Merge pull request tsenart#41 from tsenart/50p

Add 50th latency percentile to Metrics

attack_test.go

@@ -5,10 +5,10 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
+	"os"
 	"strings"
 	"testing"
 	"time"
-	"os"
 )
 
 func init() {

lib/metrics.go

@@ -12,6 +12,7 @@ import (
 type Metrics struct {
 	Latencies struct {
 		Mean time.Duration `json:"mean"`
+		P50  time.Duration `json:"50th"` // P50 is the 50th percentile upper value
 		P95  time.Duration `json:"95th"` // P95 is the 95th percentile upper value
 		P99  time.Duration `json:"99th"` // P99 is the 99th percentile upper value
 		Max  time.Duration `json:"max"`
@@ -41,7 +42,7 @@ func NewMetrics(results []Result) *Metrics {
 		StatusCodes: map[string]int{},
 	}
 	errorSet := map[string]struct{}{}
-	quants := quantile.NewTargeted(0.95, 0.99)
+	quants := quantile.NewTargeted(0.50, 0.95, 0.99)
 	totalSuccess, totalLatencies := 0, time.Duration(0)
 
 	for _, result := range results {
@@ -63,6 +64,7 @@ func NewMetrics(results []Result) *Metrics {
 
 	m.Duration = results[len(results)-1].Timestamp.Sub(results[0].Timestamp)
 	m.Latencies.Mean = time.Duration(float64(totalLatencies) / float64(m.Requests))
+	m.Latencies.P50 = time.Duration(quants.Query(0.50))
 	m.Latencies.P95 = time.Duration(quants.Query(0.95))
 	m.Latencies.P99 = time.Duration(quants.Query(0.99))
 	m.BytesIn.Mean = float64(m.BytesIn.Total) / float64(m.Requests)

lib/metrics_test.go

@@ -25,6 +25,7 @@ func TestNewMetrics(t *testing.T) {
 	for field, values := range map[string][]time.Duration{
 		"Latencies.Max":  []time.Duration{m.Latencies.Max, 100 * time.Millisecond},
 		"Latencies.Mean": []time.Duration{m.Latencies.Mean, 50 * time.Millisecond},
+		"Latencies.P50":  []time.Duration{m.Latencies.P50, 20 * time.Millisecond},
 		"Latencies.P95":  []time.Duration{m.Latencies.P95, 30 * time.Millisecond},
 		"Latencies.P99":  []time.Duration{m.Latencies.P99, 30 * time.Millisecond},
 		"Duration":       []time.Duration{m.Duration, 2 * time.Second},

lib/reporters.go

@@ -20,8 +20,8 @@ func ReportText(results []Result) ([]byte, error) {
 	w := tabwriter.NewWriter(out, 0, 8, 2, '\t', tabwriter.StripEscape)
 	fmt.Fprintf(w, "Requests\t[total]\t%d\n", m.Requests)
 	fmt.Fprintf(w, "Duration\t[total]\t%s\n", m.Duration)
-	fmt.Fprintf(w, "Latencies\t[mean, 95, 99, max]\t%s, %s, %s, %s\n",
-		m.Latencies.Mean, m.Latencies.P95, m.Latencies.P99, m.Latencies.Max)
+	fmt.Fprintf(w, "Latencies\t[mean, 50, 95, 99, max]\t%s, %s, %s, %s, %s\n",
+		m.Latencies.Mean, m.Latencies.P50, m.Latencies.P95, m.Latencies.P99, m.Latencies.Max)
 	fmt.Fprintf(w, "Bytes In\t[total, mean]\t%d, %.2f\n", m.BytesIn.Total, m.BytesIn.Mean)
 	fmt.Fprintf(w, "Bytes Out\t[total, mean]\t%d, %.2f\n", m.BytesOut.Total, m.BytesOut.Mean)
 	fmt.Fprintf(w, "Success\t[ratio]\t%.2f%%\n", m.Success*100)