From 0d22f32683038478737c1cf02564dc0ec3480a4b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1s=20Senart?= <tomas@soundcloud.com>
Date: Wed, 14 Aug 2013 21:03:03 +0200
Subject: [PATCH] No need for more than one client with internal concurrency

---
 main.go      | 18 ++++--------------
 main_test.go | 10 +++++++---
 2 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/main.go b/main.go
index f2956c6..79ea232 100644
--- a/main.go
+++ b/main.go
@@ -4,7 +4,6 @@ import (
 	"flag"
 	"io"
 	"log"
-	"math"
 	"math/rand"
 	"net/http"
 	"os"
@@ -89,23 +88,14 @@ func main() {
 }
 
 func attack(targets Targets, ordering string, rate uint, duration time.Duration, rep Reporter) {
-	// Magic formula that assumes each client can
-	// sustain 200 RPS under normal circumstances
-	clients := make([]*Client, int(math.Ceil(float64(rate)/200.0)))
-	ratePerClient := rate / uint(len(clients))
-	for i := 0; i < len(clients); i++ {
-		clients[i] = NewClient(ratePerClient)
-	}
-
 	hits := make(chan *http.Request, rate*uint((duration).Seconds()))
 	defer close(hits)
-	for i, idxs := 0, targets.Iter(ordering); i < cap(hits); i++ {
-		hits <- targets[idxs[i%len(idxs)]]
-	}
 	responses := make(chan *Response, cap(hits))
 	defer close(responses)
-	for _, client := range clients {
-		go client.Drill(hits, responses) // Attack!
+	client := NewClient(rate)
+	go client.Drill(hits, responses) // Attack!
+	for i, idxs := 0, targets.Iter(ordering); i < cap(hits); i++ {
+		hits <- targets[idxs[i%len(idxs)]]
 	}
 	// Wait for all requests to finish
 	for i := 0; i < cap(responses); i++ {
diff --git a/main_test.go b/main_test.go
index 982be0d..50736b4 100644
--- a/main_test.go
+++ b/main_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"sync/atomic"
 	"testing"
 	"time"
@@ -20,8 +21,11 @@ func TestAttackRate(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	attack(targets, "random", 50, 1*time.Second, NewTextReporter())
-	if hits := atomic.LoadUint64(&hitCount); hits != 50 {
-		t.Fatalf("Wrong number of hits: want %d, got %d\n", 50, hits)
+	rate := uint(5000)
+	rep := NewTextReporter()
+	attack(targets, "random", rate, 1*time.Second, rep)
+	if hits := atomic.LoadUint64(&hitCount); uint(hits) != rate {
+		rep.Report(os.Stdout)
+		t.Fatalf("Wrong number of hits: want %d, got %d\n", rate, hits)
 	}
 }