From b95cfc4e7445cb804777ee531716bec773a7b170 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Tue, 14 Feb 2023 15:10:56 +0300
Subject: [PATCH 01/32] use distinct client for each iteration

---
 core/scenario/requester/base.go      |  1 +
 core/scenario/requester/http.go      | 71 ++++++++++++++++++++--------
 core/scenario/requester/http_test.go |  1 +
 core/scenario/service.go             |  9 ++++
 core/scenario/service_test.go        |  4 ++
 5 files changed, 67 insertions(+), 19 deletions(-)

diff --git a/core/scenario/requester/base.go b/core/scenario/requester/base.go
index d5bbe239..ea576678 100644
--- a/core/scenario/requester/base.go
+++ b/core/scenario/requester/base.go
@@ -34,6 +34,7 @@ type Requester interface {
 	Init(ctx context.Context, ss types.ScenarioStep, url *url.URL, debug bool, ei *injection.EnvironmentInjector) error
 	Send(envs map[string]interface{}) *types.ScenarioStepResult
 	Done()
+	Type() string
 }
 
 // NewRequester is the factory method of the Requester.
diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index 1d229818..ae580751 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -73,23 +73,6 @@ func (h *HttpRequester) Init(ctx context.Context, s types.ScenarioStep, proxyAdd
 	h.dynamicRgx = regexp.MustCompile(regex.DynamicVariableRegex)
 	h.envRgx = regexp.MustCompile(regex.EnvironmentVariableRegex)
 
-	// TlsConfig
-	tlsConfig := h.initTLSConfig()
-
-	// Transport segment
-	tr := h.initTransport(tlsConfig)
-
-	// http client
-	h.client = &http.Client{Transport: tr, Timeout: time.Duration(h.packet.Timeout) * time.Second}
-	if val, ok := h.packet.Custom["disable-redirect"]; ok {
-		val := val.(bool)
-		if val {
-			h.client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
-				return http.ErrUseLastResponse
-			}
-		}
-	}
-
 	// Request instance
 	err = h.initRequestInstance()
 	if err != nil {
@@ -188,6 +171,28 @@ func (h *HttpRequester) Send(envs map[string]interface{}) (res *types.ScenarioSt
 		usableVars[k] = v
 	}
 
+	if h.client == nil {
+		h.client = &http.Client{}
+	}
+
+	// Transport segment
+	if h.client.Transport == nil {
+		h.client.Transport = h.initTransport()
+	} else {
+		h.updateTransport()
+	}
+
+	// http client
+	h.client.Timeout = time.Duration(h.packet.Timeout) * time.Second
+	if val, ok := h.packet.Custom["disable-redirect"]; ok {
+		val := val.(bool)
+		if val {
+			h.client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
+				return http.ErrUseLastResponse
+			}
+		}
+	}
+
 	durations := &duration{}
 	trace := newTrace(durations, h.proxyAddr)
 	httpReq, err := h.prepareReq(usableVars, trace)
@@ -448,9 +453,9 @@ func fetchErrType(err error) types.RequestError {
 	return requestErr
 }
 
-func (h *HttpRequester) initTransport(tlsConfig *tls.Config) *http.Transport {
+func (h *HttpRequester) initTransport() *http.Transport {
 	tr := &http.Transport{
-		TLSClientConfig:     tlsConfig,
+		TLSClientConfig:     h.initTLSConfig(),
 		Proxy:               http.ProxyURL(h.proxyAddr),
 		MaxIdleConnsPerHost: 60000,
 		MaxIdleConns:        0,
@@ -472,6 +477,26 @@ func (h *HttpRequester) initTransport(tlsConfig *tls.Config) *http.Transport {
 	return tr
 }
 
+func (h *HttpRequester) updateTransport() {
+	tr := h.client.Transport.(*http.Transport)
+	tr.TLSClientConfig = h.initTLSConfig()
+	tr.Proxy = http.ProxyURL(h.proxyAddr)
+
+	tr.DisableKeepAlives = false
+	if val, ok := h.packet.Custom["keep-alive"]; ok {
+		tr.DisableKeepAlives = !val.(bool)
+	}
+	if val, ok := h.packet.Custom["disable-compression"]; ok {
+		tr.DisableCompression = val.(bool)
+	}
+	if val, ok := h.packet.Custom["h2"]; ok {
+		val := val.(bool)
+		if val {
+			http2.ConfigureTransport(tr)
+		}
+	}
+}
+
 func (h *HttpRequester) initTLSConfig() *tls.Config {
 	tlsConfig := &tls.Config{
 		InsecureSkipVerify: true,
@@ -526,6 +551,14 @@ func (h *HttpRequester) initRequestInstance() (err error) {
 	return
 }
 
+func (h *HttpRequester) Type() string {
+	return "HTTP"
+}
+
+func (h *HttpRequester) SetClient(c *http.Client) {
+	h.client = c
+}
+
 func newTrace(duration *duration, proxyAddr *url.URL) *httptrace.ClientTrace {
 	var dnsStart, connStart, tlsStart, reqStart, serverProcessStart time.Time
 
diff --git a/core/scenario/requester/http_test.go b/core/scenario/requester/http_test.go
index 9cd7d0a5..7101e5df 100644
--- a/core/scenario/requester/http_test.go
+++ b/core/scenario/requester/http_test.go
@@ -158,6 +158,7 @@ func TestInitClient(t *testing.T) {
 		tf := func(t *testing.T) {
 			h := &HttpRequester{}
 			h.Init(test.ctx, test.scenarioItem, test.proxy, false, nil)
+			h.Send(map[string]interface{}{})
 
 			transport := h.client.Transport.(*http.Transport)
 			tls := transport.TLSClientConfig
diff --git a/core/scenario/service.go b/core/scenario/service.go
index e40e53a3..655521ad 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -23,6 +23,7 @@ package scenario
 import (
 	"context"
 	"math/rand"
+	"net/http"
 	"net/url"
 	"regexp"
 	"strconv"
@@ -109,6 +110,14 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 	s.enrichEnvFromData(envs)
 	atomic.AddInt64(&s.iterIndex, 1)
 
+	client := &http.Client{}
+	for _, sr := range requesters {
+		if sr.requester.Type() == "HTTP" {
+			// use same client throughout iteration
+			sr.requester.(*requester.HttpRequester).SetClient(client)
+		}
+	}
+
 	for _, sr := range requesters {
 		res := sr.requester.Send(envs)
 
diff --git a/core/scenario/service_test.go b/core/scenario/service_test.go
index 4bdae6dc..38fceecf 100644
--- a/core/scenario/service_test.go
+++ b/core/scenario/service_test.go
@@ -63,6 +63,10 @@ func (m *MockRequester) Done() {
 	m.DoneCalled = true
 }
 
+func (m *MockRequester) Type() string {
+	return "mock"
+}
+
 type MockSleep struct {
 	SleepCalled    bool
 	SleepCallCount int

From 907e26d215f0033e780aed8857db0d8aec24bf6c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Tue, 14 Feb 2023 17:20:04 +0300
Subject: [PATCH 02/32] refactor requester interface

---
 core/scenario/requester/base.go      | 10 ++++++---
 core/scenario/requester/http.go      | 30 ++++++++++++---------------
 core/scenario/requester/http_test.go | 17 ++++++++-------
 core/scenario/service.go             | 24 ++++++++++++++-------
 core/scenario/service_test.go        | 31 ++++++++++++++--------------
 5 files changed, 61 insertions(+), 51 deletions(-)

diff --git a/core/scenario/requester/base.go b/core/scenario/requester/base.go
index ea576678..f63377b7 100644
--- a/core/scenario/requester/base.go
+++ b/core/scenario/requester/base.go
@@ -22,6 +22,7 @@ package requester
 
 import (
 	"context"
+	"net/http"
 	"net/url"
 
 	"go.ddosify.com/ddosify/core/scenario/scripting/injection"
@@ -31,10 +32,13 @@ import (
 // Requester is the interface that abstracts different protocols' request sending implementations.
 // Protocol field in the types.ScenarioStep determines which requester implementation to use.
 type Requester interface {
-	Init(ctx context.Context, ss types.ScenarioStep, url *url.URL, debug bool, ei *injection.EnvironmentInjector) error
-	Send(envs map[string]interface{}) *types.ScenarioStepResult
-	Done()
 	Type() string
+	Done()
+}
+
+type HttpRequesterI interface {
+	Init(ctx context.Context, ss types.ScenarioStep, url *url.URL, debug bool, ei *injection.EnvironmentInjector) error
+	Send(*http.Client, map[string]interface{}) *types.ScenarioStepResult
 }
 
 // NewRequester is the factory method of the Requester.
diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index ae580751..f037281e 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -50,7 +50,6 @@ type HttpRequester struct {
 	ctx                  context.Context
 	proxyAddr            *url.URL
 	packet               types.ScenarioStep
-	client               *http.Client
 	request              *http.Request
 	ei                   *injection.EnvironmentInjector
 	containsDynamicField map[string]bool
@@ -148,10 +147,12 @@ func (h *HttpRequester) Done() {
 	// let us reuse the connections when keep-alive enabled(default)
 	// When the Job is finished, we have to Close idle connections to prevent sockets to lock in at the TIME_WAIT state.
 	// Otherwise, the next job can't use these sockets because they are reserved for the current target host.
-	h.client.CloseIdleConnections()
+
+	// TODO
+	// h.client.CloseIdleConnections()
 }
 
-func (h *HttpRequester) Send(envs map[string]interface{}) (res *types.ScenarioStepResult) {
+func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (res *types.ScenarioStepResult) {
 	var statusCode int
 	var contentLength int64
 	var requestErr types.RequestError
@@ -171,23 +172,23 @@ func (h *HttpRequester) Send(envs map[string]interface{}) (res *types.ScenarioSt
 		usableVars[k] = v
 	}
 
-	if h.client == nil {
-		h.client = &http.Client{}
+	if client == nil {
+		client = &http.Client{}
 	}
 
 	// Transport segment
-	if h.client.Transport == nil {
-		h.client.Transport = h.initTransport()
+	if client.Transport == nil {
+		client.Transport = h.initTransport()
 	} else {
-		h.updateTransport()
+		h.updateTransport(client.Transport.(*http.Transport))
 	}
 
 	// http client
-	h.client.Timeout = time.Duration(h.packet.Timeout) * time.Second
+	client.Timeout = time.Duration(h.packet.Timeout) * time.Second
 	if val, ok := h.packet.Custom["disable-redirect"]; ok {
 		val := val.(bool)
 		if val {
-			h.client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
+			client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
 				return http.ErrUseLastResponse
 			}
 		}
@@ -214,7 +215,7 @@ func (h *HttpRequester) Send(envs map[string]interface{}) (res *types.ScenarioSt
 	httpReq.Body = io.NopCloser(bytes.NewReader(copiedReqBody.Bytes()))
 
 	// Action
-	httpRes, err := h.client.Do(httpReq)
+	httpRes, err := client.Do(httpReq)
 	if err != nil {
 		requestErr = fetchErrType(err)
 		failedCaptures = h.captureEnvironmentVariables(nil, nil, extractedVars)
@@ -477,8 +478,7 @@ func (h *HttpRequester) initTransport() *http.Transport {
 	return tr
 }
 
-func (h *HttpRequester) updateTransport() {
-	tr := h.client.Transport.(*http.Transport)
+func (h *HttpRequester) updateTransport(tr *http.Transport) {
 	tr.TLSClientConfig = h.initTLSConfig()
 	tr.Proxy = http.ProxyURL(h.proxyAddr)
 
@@ -555,10 +555,6 @@ func (h *HttpRequester) Type() string {
 	return "HTTP"
 }
 
-func (h *HttpRequester) SetClient(c *http.Client) {
-	h.client = c
-}
-
 func newTrace(duration *duration, proxyAddr *url.URL) *httptrace.ClientTrace {
 	var dnsStart, connStart, tlsStart, reqStart, serverProcessStart time.Time
 
diff --git a/core/scenario/requester/http_test.go b/core/scenario/requester/http_test.go
index 7101e5df..16e9627a 100644
--- a/core/scenario/requester/http_test.go
+++ b/core/scenario/requester/http_test.go
@@ -158,9 +158,10 @@ func TestInitClient(t *testing.T) {
 		tf := func(t *testing.T) {
 			h := &HttpRequester{}
 			h.Init(test.ctx, test.scenarioItem, test.proxy, false, nil)
-			h.Send(map[string]interface{}{})
+			client := &http.Client{}
+			h.Send(client, map[string]interface{}{})
 
-			transport := h.client.Transport.(*http.Transport)
+			transport := client.Transport.(*http.Transport)
 			tls := transport.TLSClientConfig
 
 			// TLS Assert (Also check HTTP2 vs HTTP)
@@ -188,11 +189,11 @@ func TestInitClient(t *testing.T) {
 			}
 
 			// Client Assert
-			if test.client.Timeout != h.client.Timeout {
-				t.Errorf("Timeout Expected %v, Found %v", test.client.Timeout, h.client.Timeout)
+			if test.client.Timeout != client.Timeout {
+				t.Errorf("Timeout Expected %v, Found %v", test.client.Timeout, client.Timeout)
 			}
 
-			crFunc := h.client.CheckRedirect == nil
+			crFunc := client.CheckRedirect == nil
 			expectedCRFunc := test.client.CheckRedirect == nil
 			if expectedCRFunc != crFunc {
 				t.Errorf("CheckRedirect Expected %v, Found %v", expectedCRFunc, crFunc)
@@ -368,7 +369,7 @@ func TestSendOnDebugModePopulatesDebugInfo(t *testing.T) {
 		var proxy *url.URL
 		_ = h.Init(ctx, s, proxy, debug, nil)
 		envs := map[string]interface{}{}
-		res := h.Send(envs)
+		res := h.Send(http.DefaultClient, envs)
 
 		if expectedMethod != res.Method {
 			t.Errorf("Method Expected %#v, Found: \n%#v", expectedMethod, res.Method)
@@ -428,7 +429,7 @@ func TestCaptureEnvShouldSetEmptyStringWhenReqFails(t *testing.T) {
 			var proxy *url.URL
 			_ = h.Init(ctx, test.scenarioStep, proxy, debug, nil)
 			envs := map[string]interface{}{}
-			res := h.Send(envs)
+			res := h.Send(http.DefaultClient, envs)
 
 			if !reflect.DeepEqual(res.ExtractedEnvs, test.expectedExtractedEnvs) {
 				t.Errorf("Extracted env should be set empty string on req failure")
@@ -467,7 +468,7 @@ func TestAssertions(t *testing.T) {
 	h := &HttpRequester{}
 	h.Init(ctx, s, nil, false, nil)
 
-	res := h.Send(map[string]interface{}{})
+	res := h.Send(http.DefaultClient, map[string]interface{}{})
 
 	if !strings.EqualFold(res.FailedAssertions[0].Rule, rule1) {
 		t.Errorf("rule expected %s, got %s", rule1, res.FailedAssertions[0].Rule)
diff --git a/core/scenario/service.go b/core/scenario/service.go
index 655521ad..688fae1b 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -22,6 +22,7 @@ package scenario
 
 import (
 	"context"
+	"fmt"
 	"math/rand"
 	"net/http"
 	"net/url"
@@ -112,14 +113,14 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 
 	client := &http.Client{}
 	for _, sr := range requesters {
-		if sr.requester.Type() == "HTTP" {
-			// use same client throughout iteration
-			sr.requester.(*requester.HttpRequester).SetClient(client)
+		var res *types.ScenarioStepResult
+		switch sr.requester.Type() {
+		case "HTTP":
+			httpRequester := sr.requester.(requester.HttpRequesterI)
+			res = httpRequester.Send(client, envs)
+		default:
+			res = &types.ScenarioStepResult{Err: types.RequestError{Type: fmt.Sprintf("type not defined: %s", sr.requester.Type())}}
 		}
-	}
-
-	for _, sr := range requesters {
-		res := sr.requester.Send(envs)
 
 		if res.Err.Type == types.ErrorProxy || res.Err.Type == types.ErrorIntented {
 			err = &res.Err
@@ -208,7 +209,14 @@ func (s *ScenarioService) createRequesters(proxy *url.URL) (err error) {
 			},
 		)
 
-		err = r.Init(s.ctx, si, proxy, s.debug, s.ei)
+		switch r.Type() {
+		case "HTTP":
+			httpRequester := r.(requester.HttpRequesterI)
+			err = httpRequester.Init(s.ctx, si, proxy, s.debug, s.ei)
+		default:
+			err = fmt.Errorf("type not defined: %s", r.Type())
+		}
+
 		if err != nil {
 			return
 		}
diff --git a/core/scenario/service_test.go b/core/scenario/service_test.go
index 38fceecf..7c9e5960 100644
--- a/core/scenario/service_test.go
+++ b/core/scenario/service_test.go
@@ -23,6 +23,7 @@ package scenario
 import (
 	"context"
 	"fmt"
+	"net/http"
 	"net/url"
 	"reflect"
 	"testing"
@@ -33,7 +34,7 @@ import (
 	"go.ddosify.com/ddosify/core/types"
 )
 
-type MockRequester struct {
+type MockHttpRequester struct {
 	InitCalled bool
 	SendCalled bool
 	DoneCalled bool
@@ -46,7 +47,7 @@ type MockRequester struct {
 	ReturnSend *types.ScenarioStepResult
 }
 
-func (m *MockRequester) Init(ctx context.Context, s types.ScenarioStep, proxyAddr *url.URL, debug bool, ei *injection.EnvironmentInjector) (err error) {
+func (m *MockHttpRequester) Init(ctx context.Context, s types.ScenarioStep, proxyAddr *url.URL, debug bool, ei *injection.EnvironmentInjector) (err error) {
 	m.InitCalled = true
 	if m.FailInit {
 		return fmt.Errorf(m.FailInitMsg)
@@ -54,17 +55,17 @@ func (m *MockRequester) Init(ctx context.Context, s types.ScenarioStep, proxyAdd
 	return
 }
 
-func (m *MockRequester) Send(envs map[string]interface{}) (res *types.ScenarioStepResult) {
+func (m *MockHttpRequester) Send(client *http.Client, envs map[string]interface{}) (res *types.ScenarioStepResult) {
 	m.SendCalled = true
 	return m.ReturnSend
 }
 
-func (m *MockRequester) Done() {
+func (m *MockHttpRequester) Done() {
 	m.DoneCalled = true
 }
 
-func (m *MockRequester) Type() string {
-	return "mock"
+func (m *MockHttpRequester) Type() string {
+	return "HTTP"
 }
 
 type MockSleep struct {
@@ -230,11 +231,11 @@ func TestDo(t *testing.T) {
 		{
 			scenarioItemID: 1,
 			sleeper:        mockSleep,
-			requester:      &MockRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}},
+			requester:      &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}},
 		},
 		{
 			scenarioItemID: 2,
-			requester:      &MockRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}},
+			requester:      &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}},
 		},
 	}
 	service := ScenarioService{
@@ -292,19 +293,19 @@ func TestDoErrorOnSend(t *testing.T) {
 	requestersProxyError := []scenarioItemRequester{
 		{
 			scenarioItemID: 1,
-			requester:      &MockRequester{ReturnSend: &types.ScenarioStepResult{Err: types.RequestError{Type: types.ErrorProxy}}},
+			requester:      &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{Err: types.RequestError{Type: types.ErrorProxy}}},
 		},
 	}
 	requestersIntentedError := []scenarioItemRequester{
 		{
 			scenarioItemID: 1,
-			requester:      &MockRequester{ReturnSend: &types.ScenarioStepResult{Err: types.RequestError{Type: types.ErrorIntented}}},
+			requester:      &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{Err: types.RequestError{Type: types.ErrorIntented}}},
 		},
 	}
 	requestersConnError := []scenarioItemRequester{
 		{
 			scenarioItemID: 1,
-			requester:      &MockRequester{ReturnSend: &types.ScenarioStepResult{Err: types.RequestError{Type: types.ErrorConn}}},
+			requester:      &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{Err: types.RequestError{Type: types.ErrorConn}}},
 		},
 	}
 
@@ -409,10 +410,10 @@ func TestDone(t *testing.T) {
 	p2, _ := url.Parse("http://proxy_server.com:8080")
 	ctx := context.TODO()
 
-	requester1 := &MockRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}}
-	requester2 := &MockRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}}
-	requester3 := &MockRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}}
-	requester4 := &MockRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}}
+	requester1 := &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}}
+	requester2 := &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}}
+	requester3 := &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}}
+	requester4 := &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}}
 	service := ScenarioService{
 		clients: map[*url.URL][]scenarioItemRequester{
 			p1: {

From b75fc2649ac219dcd4d37892907ef8ea5ae637fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 12:38:27 +0300
Subject: [PATCH 03/32] add client pool and use same connection per host
 throughout an iteration

---
 core/engine.go                  |  18 +++++-
 core/scenario/client_pool.go    | 101 ++++++++++++++++++++++++++++++++
 core/scenario/requester/http.go |   7 +--
 core/scenario/service.go        |  21 ++++++-
 core/scenario/service_test.go   |  26 ++++++--
 5 files changed, 160 insertions(+), 13 deletions(-)
 create mode 100644 core/scenario/client_pool.go

diff --git a/core/engine.go b/core/engine.go
index 82f6b2e6..a8668cbe 100644
--- a/core/engine.go
+++ b/core/engine.go
@@ -91,11 +91,16 @@ func NewEngine(ctx context.Context, h types.Hammer) (e *engine, err error) {
 }
 
 func (e *engine) Init() (err error) {
+	e.initReqCountArr()
 	if err = e.proxyService.Init(e.hammer.Proxy); err != nil {
 		return
 	}
 
-	if err = e.scenarioService.Init(e.ctx, e.hammer.Scenario, e.proxyService.GetAll(), e.hammer.Debug); err != nil {
+	if err = e.scenarioService.Init(e.ctx, e.hammer.Scenario, e.proxyService.GetAll(), scenario.ScenarioOpts{
+		Debug:                  e.hammer.Debug,
+		IterationCount:         e.hammer.IterationCount,
+		MaxConcurrentIterCount: e.getMaxConcurrentIterCount(),
+	}); err != nil {
 		return
 	}
 
@@ -103,7 +108,6 @@ func (e *engine) Init() (err error) {
 		return
 	}
 
-	e.initReqCountArr()
 	return
 }
 
@@ -184,6 +188,16 @@ func (e *engine) stop() {
 	e.scenarioService.Done()
 }
 
+func (e *engine) getMaxConcurrentIterCount() int {
+	max := 0
+	for _, v := range e.reqCountArr {
+		if v > max {
+			max = v
+		}
+	}
+	return max
+}
+
 func (e *engine) initReqCountArr() {
 	if e.hammer.Debug {
 		e.reqCountArr = []int{1}
diff --git a/core/scenario/client_pool.go b/core/scenario/client_pool.go
new file mode 100644
index 00000000..fa0ae491
--- /dev/null
+++ b/core/scenario/client_pool.go
@@ -0,0 +1,101 @@
+package scenario
+
+import (
+	"errors"
+	"net/http"
+	"sync"
+)
+
+type clientPool struct {
+	// storage for our http.Clients
+	mu      sync.RWMutex
+	clients chan *http.Client
+	factory Factory
+}
+
+// Factory is a function to create new connections.
+type Factory func() *http.Client
+
+// NewClientPool returns a new pool based on buffered channels with an initial
+// capacity and maximum capacity. Factory is used when initial capacity is
+// greater than zero to fill the pool. A zero initialCap doesn't fill the Pool
+// until a new Get() is called. During a Get(), If there is no new client
+// available in the pool, a new client will be created via the Factory()
+// method.
+func NewClientPool(initialCap, maxCap int, factory Factory) (*clientPool, error) {
+	if initialCap < 0 || maxCap <= 0 || initialCap > maxCap {
+		return nil, errors.New("invalid capacity settings")
+	}
+
+	pool := &clientPool{
+		clients: make(chan *http.Client, maxCap),
+		factory: factory,
+	}
+
+	// create initial clients, if something goes wrong,
+	// just close the pool error out.
+	for i := 0; i < initialCap; i++ {
+		client := pool.factory()
+		pool.clients <- client
+	}
+
+	return pool, nil
+}
+
+func (c *clientPool) getConnsAndFactory() (chan *http.Client, Factory) {
+	c.mu.RLock()
+	clients := c.clients
+	factory := c.factory
+	c.mu.RUnlock()
+	return clients, factory
+}
+
+func (c *clientPool) Get() *http.Client {
+	clients, factory := c.getConnsAndFactory()
+
+	var client *http.Client
+	select {
+	case client = <-clients:
+	default:
+		client = factory()
+	}
+	return client
+}
+
+func (c *clientPool) Put(client *http.Client) error {
+	if client == nil {
+		return errors.New("client is nil. rejecting")
+	}
+
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	if c.clients == nil {
+		// pool is closed, close passed client
+		client.CloseIdleConnections()
+		return nil
+	}
+
+	// put the resource back into the pool. If the pool is full, this will
+	// block and the default case will be executed.
+	select {
+	case c.clients <- client:
+		return nil
+	default:
+		// pool is full, close passed connection
+		client.CloseIdleConnections()
+		return nil
+	}
+}
+
+func (c *clientPool) Len() int {
+	conns, _ := c.getConnsAndFactory()
+	return len(conns)
+}
+
+func (c *clientPool) Done() {
+	close(c.clients)
+	for c := range c.clients {
+		c.CloseIdleConnections()
+	}
+}
diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index f037281e..861f65de 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -456,10 +456,9 @@ func fetchErrType(err error) types.RequestError {
 
 func (h *HttpRequester) initTransport() *http.Transport {
 	tr := &http.Transport{
-		TLSClientConfig:     h.initTLSConfig(),
-		Proxy:               http.ProxyURL(h.proxyAddr),
-		MaxIdleConnsPerHost: 60000,
-		MaxIdleConns:        0,
+		TLSClientConfig: h.initTLSConfig(),
+		Proxy:           http.ProxyURL(h.proxyAddr),
+		MaxConnsPerHost: 1, // to use the same connection per host throughout an iteration
 	}
 
 	tr.DisableKeepAlives = false
diff --git a/core/scenario/service.go b/core/scenario/service.go
index 688fae1b..d7c93d50 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -46,6 +46,8 @@ type ScenarioService struct {
 	// Each scenarioItem has a requester
 	clients map[*url.URL][]scenarioItemRequester
 
+	cPool *clientPool
+
 	scenario types.Scenario
 	ctx      context.Context
 
@@ -60,13 +62,19 @@ func NewScenarioService() *ScenarioService {
 	return &ScenarioService{}
 }
 
+type ScenarioOpts struct {
+	Debug                  bool
+	IterationCount         int
+	MaxConcurrentIterCount int
+}
+
 // Init initializes the ScenarioService.clients with the given types.Scenario and proxies.
 // Passes the given ctx to the underlying requestor so we are able to control the life of each request.
 func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
-	proxies []*url.URL, debug bool) (err error) {
+	proxies []*url.URL, opts ScenarioOpts) (err error) {
 	s.scenario = scenario
 	s.ctx = ctx
-	s.debug = debug
+	s.debug = opts.Debug
 	s.clients = make(map[*url.URL][]scenarioItemRequester, len(proxies))
 
 	ei := &injection.EnvironmentInjector{}
@@ -82,6 +90,10 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 	vi := &injection.EnvironmentInjector{}
 	vi.Init()
 	s.ei = vi
+
+	// TODO: timeout and buffer
+	s.cPool, err = NewClientPool(opts.MaxConcurrentIterCount, opts.IterationCount, func() *http.Client { return &http.Client{} })
+
 	return
 }
 
@@ -111,7 +123,7 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 	s.enrichEnvFromData(envs)
 	atomic.AddInt64(&s.iterIndex, 1)
 
-	client := &http.Client{}
+	client := s.cPool.Get()
 	for _, sr := range requesters {
 		var res *types.ScenarioStepResult
 		switch sr.requester.Type() {
@@ -138,6 +150,7 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 
 		enrichEnvFromPrevStep(envs, res.ExtractedEnvs)
 	}
+	s.cPool.Put(client)
 	return
 }
 
@@ -176,6 +189,8 @@ func (s *ScenarioService) Done() {
 			r.requester.Done()
 		}
 	}
+
+	s.cPool.Done()
 }
 
 func (s *ScenarioService) getOrCreateRequesters(proxy *url.URL) (requesters []scenarioItemRequester, err error) {
diff --git a/core/scenario/service_test.go b/core/scenario/service_test.go
index 7c9e5960..5ffe7231 100644
--- a/core/scenario/service_test.go
+++ b/core/scenario/service_test.go
@@ -191,7 +191,11 @@ func TestInitService(t *testing.T) {
 
 	// Act
 	service := ScenarioService{}
-	err := service.Init(ctx, scenario, proxies, false)
+	err := service.Init(ctx, scenario, proxies, ScenarioOpts{
+		Debug:                  false,
+		IterationCount:         1,
+		MaxConcurrentIterCount: 1,
+	})
 
 	// Assert
 	if err != nil {
@@ -238,12 +242,14 @@ func TestDo(t *testing.T) {
 			requester:      &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}},
 		},
 	}
+	cPool, _ := NewClientPool(1, 1, func() *http.Client { return &http.Client{} })
 	service := ScenarioService{
 		clients: map[*url.URL][]scenarioItemRequester{
 			p1: requesters,
 		},
 		scenario: scenario,
 		ctx:      ctx,
+		cPool:    cPool,
 	}
 
 	expectedResponse := types.ScenarioResult{
@@ -322,12 +328,14 @@ func TestDoErrorOnSend(t *testing.T) {
 	}
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
+			cPool, _ := NewClientPool(1, 1, func() *http.Client { return &http.Client{} })
 			service := ScenarioService{
 				clients: map[*url.URL][]scenarioItemRequester{
 					p1: test.requesters,
 				},
 				scenario: scenario,
 				ctx:      ctx,
+				cPool:    cPool,
 			}
 
 			// Act
@@ -410,6 +418,8 @@ func TestDone(t *testing.T) {
 	p2, _ := url.Parse("http://proxy_server.com:8080")
 	ctx := context.TODO()
 
+	cPool, _ := NewClientPool(1, 1, func() *http.Client { return &http.Client{} })
+
 	requester1 := &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}}
 	requester2 := &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 2}}
 	requester3 := &MockHttpRequester{ReturnSend: &types.ScenarioStepResult{StepID: 1}}
@@ -439,8 +449,8 @@ func TestDone(t *testing.T) {
 		},
 		scenario: scenario,
 		ctx:      ctx,
+		cPool:    cPool,
 	}
-
 	// Act
 	service.Done()
 
@@ -478,7 +488,11 @@ func TestGetOrCreateRequesters(t *testing.T) {
 	ctx := context.TODO()
 
 	service := ScenarioService{}
-	service.Init(ctx, scenario, proxies, false)
+	service.Init(ctx, scenario, proxies, ScenarioOpts{
+		Debug:                  false,
+		IterationCount:         1,
+		MaxConcurrentIterCount: 1,
+	})
 
 	expectedRequesters := []scenarioItemRequester{{scenarioItemID: 1, requester: &requester.HttpRequester{}}}
 	expectedClients := map[*url.URL][]scenarioItemRequester{
@@ -523,7 +537,11 @@ func TestGetOrCreateRequestersNewProxy(t *testing.T) {
 	ctx := context.TODO()
 
 	service := ScenarioService{}
-	service.Init(ctx, scenario, proxies, false)
+	service.Init(ctx, scenario, proxies, ScenarioOpts{
+		Debug:                  false,
+		IterationCount:         1,
+		MaxConcurrentIterCount: 1,
+	})
 
 	expectedRequesters := []scenarioItemRequester{{scenarioItemID: 1, requester: &requester.HttpRequester{}}}
 

From a358b4348c577f9c971cf00b1f9799dc74a82d9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 14:44:52 +0300
Subject: [PATCH 04/32] update benchmark test exit code

---
 main_benchmark_test.go | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/main_benchmark_test.go b/main_benchmark_test.go
index ecf0bfb0..ff340795 100644
--- a/main_benchmark_test.go
+++ b/main_benchmark_test.go
@@ -214,10 +214,9 @@ func BenchmarkEngines(t *testing.B) {
 
 		})
 
-		if success {
-			os.Exit(0)
+		if !success {
+			os.Exit(1)
 		}
-		os.Exit(1)
 	}
 }
 

From 0b5f4fcf2bcbd834df00590d87b46ac24b3b827b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 14:49:49 +0300
Subject: [PATCH 05/32] update jenkins benchmark

---
 Jenkinsfile_benchmark | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Jenkinsfile_benchmark b/Jenkinsfile_benchmark
index 8e24202a..22fb29af 100644
--- a/Jenkinsfile_benchmark
+++ b/Jenkinsfile_benchmark
@@ -14,7 +14,7 @@ pipeline {
     stage('Performance Test') {
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
+          sh 'GOCACHE=/tmp/ set -o pipefail && go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
         }
       }
     }
@@ -29,7 +29,7 @@ pipeline {
       }
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
+          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && GOCACHE=/tmp/ set -o pipefail && go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
           sh "git checkout ${BRANCH_NAME}"
           sh "benchstat -alpha 1.01 --sort delta gobench_develop.txt gobench_branch.txt | tee gobench_branch_result.txt"
           sh "benchstat -alpha 1.01 --sort delta --html gobench_develop.txt gobench_branch.txt > 00_gobench_result.html && echo ${BUILD_URL}artifact/00_gobench_result.html"

From 4ed6d405cf94a6da68161afb2749393047937f84 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 14:51:33 +0300
Subject: [PATCH 06/32] update jenkins

---
 Jenkinsfile_benchmark | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Jenkinsfile_benchmark b/Jenkinsfile_benchmark
index 22fb29af..21b4f74a 100644
--- a/Jenkinsfile_benchmark
+++ b/Jenkinsfile_benchmark
@@ -14,7 +14,7 @@ pipeline {
     stage('Performance Test') {
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'GOCACHE=/tmp/ set -o pipefail && go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
+          sh 'set -o pipefail && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
         }
       }
     }
@@ -29,7 +29,7 @@ pipeline {
       }
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && GOCACHE=/tmp/ set -o pipefail && go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
+          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && set -o pipefail && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
           sh "git checkout ${BRANCH_NAME}"
           sh "benchstat -alpha 1.01 --sort delta gobench_develop.txt gobench_branch.txt | tee gobench_branch_result.txt"
           sh "benchstat -alpha 1.01 --sort delta --html gobench_develop.txt gobench_branch.txt > 00_gobench_result.html && echo ${BUILD_URL}artifact/00_gobench_result.html"

From fc1b4b76d392bac2ce966925a767134c32115f33 Mon Sep 17 00:00:00 2001
From: fatihbaltaci <baltacifatih14@gmail.com>
Date: Thu, 16 Feb 2023 15:00:49 +0300
Subject: [PATCH 07/32] Update jenkinsfile

---
 Jenkinsfile_benchmark | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Jenkinsfile_benchmark b/Jenkinsfile_benchmark
index 21b4f74a..f45f930f 100644
--- a/Jenkinsfile_benchmark
+++ b/Jenkinsfile_benchmark
@@ -14,7 +14,8 @@ pipeline {
     stage('Performance Test') {
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'set -o pipefail && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
+          sh 'set -o pipefail'
+          sh 'GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
         }
       }
     }
@@ -29,7 +30,7 @@ pipeline {
       }
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && set -o pipefail && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
+          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
           sh "git checkout ${BRANCH_NAME}"
           sh "benchstat -alpha 1.01 --sort delta gobench_develop.txt gobench_branch.txt | tee gobench_branch_result.txt"
           sh "benchstat -alpha 1.01 --sort delta --html gobench_develop.txt gobench_branch.txt > 00_gobench_result.html && echo ${BUILD_URL}artifact/00_gobench_result.html"

From 56eff2a3795078cf03df69de4f849250bd40b85c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 15:03:21 +0300
Subject: [PATCH 08/32] add connection reuse to conf

---
 config/json.go           | 33 ++++++++++++++++++---------------
 core/engine.go           |  1 +
 core/scenario/service.go | 11 +++++++++--
 core/types/hammer.go     |  3 +++
 4 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/config/json.go b/config/json.go
index 0d80fd61..df62a70b 100644
--- a/config/json.go
+++ b/config/json.go
@@ -144,26 +144,28 @@ func (c *CsvConf) UnmarshalJSON(data []byte) error {
 }
 
 type JsonReader struct {
-	ReqCount     *int                   `json:"request_count"`
-	IterCount    *int                   `json:"iteration_count"`
-	LoadType     string                 `json:"load_type"`
-	Duration     int                    `json:"duration"`
-	TimeRunCount timeRunCount           `json:"manual_load"`
-	Steps        []step                 `json:"steps"`
-	Output       string                 `json:"output"`
-	Proxy        string                 `json:"proxy"`
-	Envs         map[string]interface{} `json:"env"`
-	Data         map[string]CsvConf     `json:"data"`
-	Debug        bool                   `json:"debug"`
-	SamplingRate *int                   `json:"sampling_rate"`
+	ReqCount        *int                   `json:"request_count"`
+	IterCount       *int                   `json:"iteration_count"`
+	LoadType        string                 `json:"load_type"`
+	Duration        int                    `json:"duration"`
+	TimeRunCount    timeRunCount           `json:"manual_load"`
+	Steps           []step                 `json:"steps"`
+	Output          string                 `json:"output"`
+	Proxy           string                 `json:"proxy"`
+	Envs            map[string]interface{} `json:"env"`
+	Data            map[string]CsvConf     `json:"data"`
+	Debug           bool                   `json:"debug"`
+	SamplingRate    *int                   `json:"sampling_rate"`
+	ConnectionReuse bool                   `json:"connection_reuse"`
 }
 
 func (j *JsonReader) UnmarshalJSON(data []byte) error {
 	type jsonReaderAlias JsonReader
 	defaultFields := &jsonReaderAlias{
-		LoadType: types.DefaultLoadType,
-		Duration: types.DefaultDuration,
-		Output:   types.DefaultOutputType,
+		LoadType:        types.DefaultLoadType,
+		Duration:        types.DefaultDuration,
+		Output:          types.DefaultOutputType,
+		ConnectionReuse: true,
 	}
 
 	err := json.Unmarshal(data, defaultFields)
@@ -275,6 +277,7 @@ func (j *JsonReader) CreateHammer() (h types.Hammer, err error) {
 		ReportDestination: j.Output,
 		Debug:             j.Debug,
 		SamplingRate:      samplingRate,
+		ConnectionReuse:   j.ConnectionReuse,
 	}
 	return
 }
diff --git a/core/engine.go b/core/engine.go
index a8668cbe..35f00f72 100644
--- a/core/engine.go
+++ b/core/engine.go
@@ -100,6 +100,7 @@ func (e *engine) Init() (err error) {
 		Debug:                  e.hammer.Debug,
 		IterationCount:         e.hammer.IterationCount,
 		MaxConcurrentIterCount: e.getMaxConcurrentIterCount(),
+		ConnectionReuse:        e.hammer.ConnectionReuse,
 	}); err != nil {
 		return
 	}
diff --git a/core/scenario/service.go b/core/scenario/service.go
index d7c93d50..f2059c82 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -66,6 +66,7 @@ type ScenarioOpts struct {
 	Debug                  bool
 	IterationCount         int
 	MaxConcurrentIterCount int
+	ConnectionReuse        bool
 }
 
 // Init initializes the ScenarioService.clients with the given types.Scenario and proxies.
@@ -91,8 +92,14 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 	vi.Init()
 	s.ei = vi
 
-	// TODO: timeout and buffer
-	s.cPool, err = NewClientPool(opts.MaxConcurrentIterCount, opts.IterationCount, func() *http.Client { return &http.Client{} })
+	initialClientCount := opts.MaxConcurrentIterCount
+	if !opts.ConnectionReuse {
+		// TODO: timeout and buffer
+		initialClientCount = opts.IterationCount
+	}
+	maxClientCount := opts.IterationCount
+
+	s.cPool, err = NewClientPool(initialClientCount, maxClientCount, func() *http.Client { return &http.Client{} })
 
 	return
 }
diff --git a/core/types/hammer.go b/core/types/hammer.go
index d0c9537e..86417665 100644
--- a/core/types/hammer.go
+++ b/core/types/hammer.go
@@ -85,6 +85,9 @@ type Hammer struct {
 
 	// Sampling rate
 	SamplingRate int
+
+	// Connection reuse
+	ConnectionReuse bool
 }
 
 // Validate validates attack metadata and executes the validation methods of the services.

From 6a7d09a473bf3316b7a9a65d7bd40624e76fd5fd Mon Sep 17 00:00:00 2001
From: fatihbaltaci <baltacifatih14@gmail.com>
Date: Thu, 16 Feb 2023 15:10:30 +0300
Subject: [PATCH 09/32] Update jenkinsfile

---
 Jenkinsfile_benchmark | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/Jenkinsfile_benchmark b/Jenkinsfile_benchmark
index f45f930f..21b4f74a 100644
--- a/Jenkinsfile_benchmark
+++ b/Jenkinsfile_benchmark
@@ -14,8 +14,7 @@ pipeline {
     stage('Performance Test') {
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'set -o pipefail'
-          sh 'GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
+          sh 'set -o pipefail && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu.out -memprof=mem.out -tracef=trace.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_branch.txt'
         }
       }
     }
@@ -30,7 +29,7 @@ pipeline {
       }
       steps {
         lock('multi_branch_server_benchmark') {
-          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
+          sh 'git fetch origin develop:develop ||  git checkout develop && git pull && set -o pipefail && GOCACHE=/tmp/ go test -benchmem -benchtime=1x -cpuprof=cpu_develop.out -memprof=mem_develop.out -tracef=trace_develop.out -run=^$ -bench ^BenchmarkEngines/$ -count 1 | tee gobench_develop.txt'
           sh "git checkout ${BRANCH_NAME}"
           sh "benchstat -alpha 1.01 --sort delta gobench_develop.txt gobench_branch.txt | tee gobench_branch_result.txt"
           sh "benchstat -alpha 1.01 --sort delta --html gobench_develop.txt gobench_branch.txt > 00_gobench_result.html && echo ${BUILD_URL}artifact/00_gobench_result.html"

From 349d3f807d11f6c555f2066c3d5cc38043db9394 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 18:21:28 +0300
Subject: [PATCH 10/32] change pool init count

---
 core/scenario/service.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/scenario/service.go b/core/scenario/service.go
index f2059c82..a734cb25 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -92,7 +92,7 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 	vi.Init()
 	s.ei = vi
 
-	initialClientCount := opts.MaxConcurrentIterCount
+	initialClientCount := opts.MaxConcurrentIterCount * 3
 	if !opts.ConnectionReuse {
 		// TODO: timeout and buffer
 		initialClientCount = opts.IterationCount

From ddfd91e3eae8445f16091b9421636bf9d5f4ef10 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 18:27:23 +0300
Subject: [PATCH 11/32] fix hammer tests

---
 config/json_test.go | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/config/json_test.go b/config/json_test.go
index 5408cbc1..687aed88 100644
--- a/config/json_test.go
+++ b/config/json_test.go
@@ -55,7 +55,8 @@ func TestCreateHammerDefaultValues(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -110,7 +111,8 @@ func TestCreateHammer(t *testing.T) {
 			Strategy: "single",
 			Addr:     addr,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -165,7 +167,8 @@ func TestCreateHammerWithIterationCountInsteadOfReqCount(t *testing.T) {
 			Strategy: "single",
 			Addr:     addr,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -223,7 +226,8 @@ func TestCreateHammerWithIterationCountOverridesReqCount(t *testing.T) {
 			Strategy: "single",
 			Addr:     addr,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -258,7 +262,8 @@ func TestCreateHammerManualLoad(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -293,7 +298,8 @@ func TestCreateHammerManualLoadOverrideOthers(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -551,7 +557,8 @@ func TestCreateHammerTLSWithOnlyCertPath(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -596,7 +603,8 @@ func TestCreateHammerTLSWithOnlyKeyPath(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -632,7 +640,8 @@ func TestCreateHammerTLSWithWithEmptyPath(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate: types.DefaultSamplingCount,
+		SamplingRate:    types.DefaultSamplingCount,
+		ConnectionReuse: true,
 	}
 
 	h, err := jsonReader.CreateHammer()

From 43c4ed25640c981a51d223ffe1219dc33217151d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 18:39:41 +0300
Subject: [PATCH 12/32] change pool count

---
 core/scenario/client_pool.go | 82 ++++++++++++++++++++++++------------
 1 file changed, 55 insertions(+), 27 deletions(-)

diff --git a/core/scenario/client_pool.go b/core/scenario/client_pool.go
index fa0ae491..4ad28add 100644
--- a/core/scenario/client_pool.go
+++ b/core/scenario/client_pool.go
@@ -2,15 +2,15 @@ package scenario
 
 import (
 	"errors"
+	"fmt"
 	"net/http"
-	"sync"
 )
 
 type clientPool struct {
 	// storage for our http.Clients
-	mu      sync.RWMutex
-	clients chan *http.Client
+	clients []chan *http.Client
 	factory Factory
+	N       int
 }
 
 // Factory is a function to create new connections.
@@ -27,37 +27,45 @@ func NewClientPool(initialCap, maxCap int, factory Factory) (*clientPool, error)
 		return nil, errors.New("invalid capacity settings")
 	}
 
+	N := 4
+
 	pool := &clientPool{
-		clients: make(chan *http.Client, maxCap),
+		clients: make([]chan *http.Client, N),
 		factory: factory,
+		N:       N,
+	}
+
+	for i := 0; i < N; i++ {
+		pool.clients[i] = make(chan *http.Client, maxCap/N)
 	}
 
 	// create initial clients, if something goes wrong,
 	// just close the pool error out.
 	for i := 0; i < initialCap; i++ {
 		client := pool.factory()
-		pool.clients <- client
+		pool.clients[i%N] <- client
 	}
 
 	return pool, nil
 }
 
-func (c *clientPool) getConnsAndFactory() (chan *http.Client, Factory) {
-	c.mu.RLock()
-	clients := c.clients
-	factory := c.factory
-	c.mu.RUnlock()
-	return clients, factory
-}
-
 func (c *clientPool) Get() *http.Client {
-	clients, factory := c.getConnsAndFactory()
-
 	var client *http.Client
+	// TODO N = 4
 	select {
-	case client = <-clients:
+	case client = <-c.clients[0]:
+	case client = <-c.clients[1]:
+	case client = <-c.clients[2]:
+	case client = <-c.clients[3]:
+	// case client = <-c.clients[4]:
+	// case client = <-c.clients[5]:
+	// case client = <-c.clients[6]:
+	// case client = <-c.clients[7]:
+	// case client = <-c.clients[8]:
+	// case client = <-c.clients[9]:
+
 	default:
-		client = factory()
+		client = c.factory()
 	}
 	return client
 }
@@ -67,9 +75,6 @@ func (c *clientPool) Put(client *http.Client) error {
 		return errors.New("client is nil. rejecting")
 	}
 
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
 	if c.clients == nil {
 		// pool is closed, close passed client
 		client.CloseIdleConnections()
@@ -79,23 +84,46 @@ func (c *clientPool) Put(client *http.Client) error {
 	// put the resource back into the pool. If the pool is full, this will
 	// block and the default case will be executed.
 	select {
-	case c.clients <- client:
+	case c.clients[0] <- client:
+		return nil
+	case c.clients[1] <- client:
+		return nil
+	case c.clients[2] <- client:
 		return nil
+	case c.clients[3] <- client:
+		return nil
+	// case c.clients[4] <- client:
+	// 	return nil
+	// case c.clients[5] <- client:
+	// 	return nil
+	// case c.clients[6] <- client:
+	// 	return nil
+	// case c.clients[7] <- client:
+	// 	return nil
+	// case c.clients[8] <- client:
+	// 	return nil
+	// case c.clients[9] <- client:
+	// 	return nil
+
 	default:
-		// pool is full, close passed connection
+		// pool is full, close passed client
 		client.CloseIdleConnections()
 		return nil
 	}
 }
 
 func (c *clientPool) Len() int {
-	conns, _ := c.getConnsAndFactory()
-	return len(conns)
+	return len(c.clients)
 }
 
 func (c *clientPool) Done() {
-	close(c.clients)
-	for c := range c.clients {
-		c.CloseIdleConnections()
+	fmt.Println(c.Len())
+	for i := 0; i < c.N; i++ {
+		close(c.clients[i])
+	}
+	for _, cp := range c.clients {
+		for c := range cp {
+			c.CloseIdleConnections()
+		}
 	}
 }

From 990638777ebea4110252f1a495d10888ad8cf488 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 18:45:53 +0300
Subject: [PATCH 13/32] change init client count

---
 core/scenario/service.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/scenario/service.go b/core/scenario/service.go
index a734cb25..af03627a 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -92,7 +92,7 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 	vi.Init()
 	s.ei = vi
 
-	initialClientCount := opts.MaxConcurrentIterCount * 3
+	initialClientCount := opts.MaxConcurrentIterCount * 10
 	if !opts.ConnectionReuse {
 		// TODO: timeout and buffer
 		initialClientCount = opts.IterationCount

From 311dcc56b099b77c1cacc8a24a98132ca7ec64c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Thu, 16 Feb 2023 19:03:17 +0300
Subject: [PATCH 14/32] change max client count

---
 core/scenario/service.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/scenario/service.go b/core/scenario/service.go
index af03627a..db123b15 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -97,7 +97,7 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 		// TODO: timeout and buffer
 		initialClientCount = opts.IterationCount
 	}
-	maxClientCount := opts.IterationCount
+	maxClientCount := opts.IterationCount / 2
 
 	s.cPool, err = NewClientPool(initialClientCount, maxClientCount, func() *http.Client { return &http.Client{} })
 

From 30abd1b8513b0e633c8f84903242be6ef6563acb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 12:25:03 +0300
Subject: [PATCH 15/32] try one client, reuse port

---
 core/scenario/requester/base.go |  2 +-
 core/scenario/requester/http.go | 35 +++++++++++++++++++++++++--------
 core/scenario/service.go        | 28 +++++++++++++++-----------
 3 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/core/scenario/requester/base.go b/core/scenario/requester/base.go
index f63377b7..db8a7d40 100644
--- a/core/scenario/requester/base.go
+++ b/core/scenario/requester/base.go
@@ -38,7 +38,7 @@ type Requester interface {
 
 type HttpRequesterI interface {
 	Init(ctx context.Context, ss types.ScenarioStep, url *url.URL, debug bool, ei *injection.EnvironmentInjector) error
-	Send(*http.Client, map[string]interface{}) *types.ScenarioStepResult
+	Send(client *http.Client, envs map[string]interface{}, hostPortMap map[string]string) *types.ScenarioStepResult
 }
 
 // NewRequester is the factory method of the Requester.
diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index 861f65de..f6832729 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -27,6 +27,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	"net/http/httptrace"
 	"net/url"
@@ -37,6 +38,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
+	reuse "github.com/libp2p/go-reuseport"
 	"go.ddosify.com/ddosify/core/scenario/scripting/assertion"
 	"go.ddosify.com/ddosify/core/scenario/scripting/assertion/evaluator"
 	"go.ddosify.com/ddosify/core/scenario/scripting/extraction"
@@ -152,7 +154,7 @@ func (h *HttpRequester) Done() {
 	// h.client.CloseIdleConnections()
 }
 
-func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (res *types.ScenarioStepResult) {
+func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}, hostPortMap map[string]string) (res *types.ScenarioStepResult) {
 	var statusCode int
 	var contentLength int64
 	var requestErr types.RequestError
@@ -178,9 +180,9 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (
 
 	// Transport segment
 	if client.Transport == nil {
-		client.Transport = h.initTransport()
+		client.Transport = h.initTransport(hostPortMap)
 	} else {
-		h.updateTransport(client.Transport.(*http.Transport))
+		h.updateTransport(client.Transport.(*http.Transport), hostPortMap)
 	}
 
 	// http client
@@ -195,7 +197,7 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (
 	}
 
 	durations := &duration{}
-	trace := newTrace(durations, h.proxyAddr)
+	trace := newTrace(durations, h.proxyAddr, h.packet.URL, hostPortMap)
 	httpReq, err := h.prepareReq(usableVars, trace)
 
 	if err != nil { // could not prepare req
@@ -454,11 +456,18 @@ func fetchErrType(err error) types.RequestError {
 	return requestErr
 }
 
-func (h *HttpRequester) initTransport() *http.Transport {
+func (h *HttpRequester) initTransport(hostPortMap map[string]string) *http.Transport {
 	tr := &http.Transport{
 		TLSClientConfig: h.initTLSConfig(),
 		Proxy:           http.ProxyURL(h.proxyAddr),
-		MaxConnsPerHost: 1, // to use the same connection per host throughout an iteration
+		// MaxConnsPerHost: 1, // to use the same connection per host throughout an iteration
+		Dial: func(network, addr string) (net.Conn, error) {
+			if localAddr, ok := hostPortMap[h.packet.URL]; ok {
+				return reuse.Dial(network, localAddr, addr)
+			} else {
+				return net.Dial(network, addr)
+			}
+		},
 	}
 
 	tr.DisableKeepAlives = false
@@ -477,10 +486,19 @@ func (h *HttpRequester) initTransport() *http.Transport {
 	return tr
 }
 
-func (h *HttpRequester) updateTransport(tr *http.Transport) {
+func (h *HttpRequester) updateTransport(tr *http.Transport, hostPortMap map[string]string) {
 	tr.TLSClientConfig = h.initTLSConfig()
 	tr.Proxy = http.ProxyURL(h.proxyAddr)
 
+	// TODO check
+	tr.Dial = func(network, addr string) (net.Conn, error) {
+		if localAddr, ok := hostPortMap[h.packet.URL]; ok {
+			return reuse.Dial(network, localAddr, addr)
+		} else {
+			return net.Dial(network, addr)
+		}
+	}
+
 	tr.DisableKeepAlives = false
 	if val, ok := h.packet.Custom["keep-alive"]; ok {
 		tr.DisableKeepAlives = !val.(bool)
@@ -554,7 +572,7 @@ func (h *HttpRequester) Type() string {
 	return "HTTP"
 }
 
-func newTrace(duration *duration, proxyAddr *url.URL) *httptrace.ClientTrace {
+func newTrace(duration *duration, proxyAddr *url.URL, reqUrl string, hostPortMap map[string]string) *httptrace.ClientTrace {
 	var dnsStart, connStart, tlsStart, reqStart, serverProcessStart time.Time
 
 	// According to the doc in the trace.go;
@@ -625,6 +643,7 @@ func newTrace(duration *duration, proxyAddr *url.URL) *httptrace.ClientTrace {
 				reqStart = time.Now()
 			}
 			m.Unlock()
+			hostPortMap[reqUrl] = connInfo.Conn.LocalAddr().String()
 		},
 		WroteRequest: func(w httptrace.WroteRequestInfo) {
 			m.Lock()
diff --git a/core/scenario/service.go b/core/scenario/service.go
index db123b15..237c2e70 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -46,7 +46,8 @@ type ScenarioService struct {
 	// Each scenarioItem has a requester
 	clients map[*url.URL][]scenarioItemRequester
 
-	cPool *clientPool
+	cPool  *clientPool
+	client *http.Client
 
 	scenario types.Scenario
 	ctx      context.Context
@@ -92,14 +93,15 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 	vi.Init()
 	s.ei = vi
 
-	initialClientCount := opts.MaxConcurrentIterCount * 10
-	if !opts.ConnectionReuse {
-		// TODO: timeout and buffer
-		initialClientCount = opts.IterationCount
-	}
-	maxClientCount := opts.IterationCount / 2
+	// initialClientCount := opts.MaxConcurrentIterCount
+	// if !opts.ConnectionReuse {
+	// 	// TODO: timeout and buffer
+	// 	initialClientCount = opts.IterationCount
+	// }
+	// maxClientCount := opts.IterationCount
+	// s.cPool, err = NewClientPool(initialClientCount, maxClientCount, func() *http.Client { return &http.Client{} })
 
-	s.cPool, err = NewClientPool(initialClientCount, maxClientCount, func() *http.Client { return &http.Client{} })
+	s.client = &http.Client{}
 
 	return
 }
@@ -130,13 +132,15 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 	s.enrichEnvFromData(envs)
 	atomic.AddInt64(&s.iterIndex, 1)
 
-	client := s.cPool.Get()
+	// client := s.cPool.Get()
+
+	urlPortMap := make(map[string]string)
 	for _, sr := range requesters {
 		var res *types.ScenarioStepResult
 		switch sr.requester.Type() {
 		case "HTTP":
 			httpRequester := sr.requester.(requester.HttpRequesterI)
-			res = httpRequester.Send(client, envs)
+			res = httpRequester.Send(s.client, envs, urlPortMap) // TODO
 		default:
 			res = &types.ScenarioStepResult{Err: types.RequestError{Type: fmt.Sprintf("type not defined: %s", sr.requester.Type())}}
 		}
@@ -157,7 +161,7 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 
 		enrichEnvFromPrevStep(envs, res.ExtractedEnvs)
 	}
-	s.cPool.Put(client)
+	// s.cPool.Put(client)
 	return
 }
 
@@ -197,7 +201,7 @@ func (s *ScenarioService) Done() {
 		}
 	}
 
-	s.cPool.Done()
+	// s.cPool.Done()
 }
 
 func (s *ScenarioService) getOrCreateRequesters(proxy *url.URL) (requesters []scenarioItemRequester, err error) {

From e313f1752393cb0341e113af54d091aabc1d34c9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 12:26:56 +0300
Subject: [PATCH 16/32] go mod

---
 go.mod | 1 +
 go.sum | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/go.mod b/go.mod
index d7da8751..2d3a60b2 100644
--- a/go.mod
+++ b/go.mod
@@ -21,6 +21,7 @@ require (
 	github.com/go-ole/go-ole v1.2.6 // indirect
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
 	github.com/jaswdr/faker v1.10.2 // indirect
+	github.com/libp2p/go-reuseport v0.2.0 // indirect
 	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
 	github.com/mattn/go-isatty v0.0.14 // indirect
 	github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c // indirect
diff --git a/go.sum b/go.sum
index ffeba571..aa90e953 100644
--- a/go.sum
+++ b/go.sum
@@ -24,6 +24,8 @@ github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/jaswdr/faker v1.10.2 h1:GK03wuDqa8V6BE+2VRr3DJ/G4T0iUDCzVoBCj5TM4b8=
 github.com/jaswdr/faker v1.10.2/go.mod h1:x7ZlyB1AZqwqKZgyQlnqEG8FDptmHlncA5u2zY/yi6w=
+github.com/libp2p/go-reuseport v0.2.0 h1:18PRvIMlpY6ZK85nIAicSBuXXvrYoSw3dsBAR7zc560=
+github.com/libp2p/go-reuseport v0.2.0/go.mod h1:bvVho6eLMm6Bz5hmU0LYN3ixd3nPPvtIlaURZZgOY4k=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 h1:6E+4a0GO5zZEnZ81pIr0yLvtUWk2if982qA3F3QD6H4=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0/go.mod h1:zJYVVT2jmtg6P3p1VtQj7WsuWi/y4VnjVBn7F8KPB3I=
 github.com/mattn/go-colorable v0.1.9/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=

From 463fa69093dba4699361d8a98aa643a467acc0c1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 12:36:08 +0300
Subject: [PATCH 17/32] go back to client pool

---
 core/scenario/client_pool.go    | 59 +++++----------------------------
 core/scenario/requester/base.go |  2 +-
 core/scenario/requester/http.go | 35 +++++--------------
 core/scenario/service.go        | 27 ++++++---------
 go.mod                          |  1 -
 go.sum                          |  2 --
 6 files changed, 28 insertions(+), 98 deletions(-)

diff --git a/core/scenario/client_pool.go b/core/scenario/client_pool.go
index 4ad28add..4892bc5e 100644
--- a/core/scenario/client_pool.go
+++ b/core/scenario/client_pool.go
@@ -2,13 +2,12 @@ package scenario
 
 import (
 	"errors"
-	"fmt"
 	"net/http"
 )
 
 type clientPool struct {
 	// storage for our http.Clients
-	clients []chan *http.Client
+	clients chan *http.Client
 	factory Factory
 	N       int
 }
@@ -27,23 +26,16 @@ func NewClientPool(initialCap, maxCap int, factory Factory) (*clientPool, error)
 		return nil, errors.New("invalid capacity settings")
 	}
 
-	N := 4
-
 	pool := &clientPool{
-		clients: make([]chan *http.Client, N),
+		clients: make(chan *http.Client, maxCap),
 		factory: factory,
-		N:       N,
-	}
-
-	for i := 0; i < N; i++ {
-		pool.clients[i] = make(chan *http.Client, maxCap/N)
 	}
 
 	// create initial clients, if something goes wrong,
 	// just close the pool error out.
 	for i := 0; i < initialCap; i++ {
 		client := pool.factory()
-		pool.clients[i%N] <- client
+		pool.clients <- client
 	}
 
 	return pool, nil
@@ -51,19 +43,8 @@ func NewClientPool(initialCap, maxCap int, factory Factory) (*clientPool, error)
 
 func (c *clientPool) Get() *http.Client {
 	var client *http.Client
-	// TODO N = 4
 	select {
-	case client = <-c.clients[0]:
-	case client = <-c.clients[1]:
-	case client = <-c.clients[2]:
-	case client = <-c.clients[3]:
-	// case client = <-c.clients[4]:
-	// case client = <-c.clients[5]:
-	// case client = <-c.clients[6]:
-	// case client = <-c.clients[7]:
-	// case client = <-c.clients[8]:
-	// case client = <-c.clients[9]:
-
+	case client = <-c.clients:
 	default:
 		client = c.factory()
 	}
@@ -84,27 +65,8 @@ func (c *clientPool) Put(client *http.Client) error {
 	// put the resource back into the pool. If the pool is full, this will
 	// block and the default case will be executed.
 	select {
-	case c.clients[0] <- client:
-		return nil
-	case c.clients[1] <- client:
+	case c.clients <- client:
 		return nil
-	case c.clients[2] <- client:
-		return nil
-	case c.clients[3] <- client:
-		return nil
-	// case c.clients[4] <- client:
-	// 	return nil
-	// case c.clients[5] <- client:
-	// 	return nil
-	// case c.clients[6] <- client:
-	// 	return nil
-	// case c.clients[7] <- client:
-	// 	return nil
-	// case c.clients[8] <- client:
-	// 	return nil
-	// case c.clients[9] <- client:
-	// 	return nil
-
 	default:
 		// pool is full, close passed client
 		client.CloseIdleConnections()
@@ -117,13 +79,8 @@ func (c *clientPool) Len() int {
 }
 
 func (c *clientPool) Done() {
-	fmt.Println(c.Len())
-	for i := 0; i < c.N; i++ {
-		close(c.clients[i])
-	}
-	for _, cp := range c.clients {
-		for c := range cp {
-			c.CloseIdleConnections()
-		}
+	close(c.clients)
+	for c := range c.clients {
+		c.CloseIdleConnections()
 	}
 }
diff --git a/core/scenario/requester/base.go b/core/scenario/requester/base.go
index db8a7d40..25547bac 100644
--- a/core/scenario/requester/base.go
+++ b/core/scenario/requester/base.go
@@ -38,7 +38,7 @@ type Requester interface {
 
 type HttpRequesterI interface {
 	Init(ctx context.Context, ss types.ScenarioStep, url *url.URL, debug bool, ei *injection.EnvironmentInjector) error
-	Send(client *http.Client, envs map[string]interface{}, hostPortMap map[string]string) *types.ScenarioStepResult
+	Send(client *http.Client, envs map[string]interface{}) *types.ScenarioStepResult
 }
 
 // NewRequester is the factory method of the Requester.
diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index f6832729..861f65de 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -27,7 +27,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net"
 	"net/http"
 	"net/http/httptrace"
 	"net/url"
@@ -38,7 +37,6 @@ import (
 	"time"
 
 	"github.com/google/uuid"
-	reuse "github.com/libp2p/go-reuseport"
 	"go.ddosify.com/ddosify/core/scenario/scripting/assertion"
 	"go.ddosify.com/ddosify/core/scenario/scripting/assertion/evaluator"
 	"go.ddosify.com/ddosify/core/scenario/scripting/extraction"
@@ -154,7 +152,7 @@ func (h *HttpRequester) Done() {
 	// h.client.CloseIdleConnections()
 }
 
-func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}, hostPortMap map[string]string) (res *types.ScenarioStepResult) {
+func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (res *types.ScenarioStepResult) {
 	var statusCode int
 	var contentLength int64
 	var requestErr types.RequestError
@@ -180,9 +178,9 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}, h
 
 	// Transport segment
 	if client.Transport == nil {
-		client.Transport = h.initTransport(hostPortMap)
+		client.Transport = h.initTransport()
 	} else {
-		h.updateTransport(client.Transport.(*http.Transport), hostPortMap)
+		h.updateTransport(client.Transport.(*http.Transport))
 	}
 
 	// http client
@@ -197,7 +195,7 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}, h
 	}
 
 	durations := &duration{}
-	trace := newTrace(durations, h.proxyAddr, h.packet.URL, hostPortMap)
+	trace := newTrace(durations, h.proxyAddr)
 	httpReq, err := h.prepareReq(usableVars, trace)
 
 	if err != nil { // could not prepare req
@@ -456,18 +454,11 @@ func fetchErrType(err error) types.RequestError {
 	return requestErr
 }
 
-func (h *HttpRequester) initTransport(hostPortMap map[string]string) *http.Transport {
+func (h *HttpRequester) initTransport() *http.Transport {
 	tr := &http.Transport{
 		TLSClientConfig: h.initTLSConfig(),
 		Proxy:           http.ProxyURL(h.proxyAddr),
-		// MaxConnsPerHost: 1, // to use the same connection per host throughout an iteration
-		Dial: func(network, addr string) (net.Conn, error) {
-			if localAddr, ok := hostPortMap[h.packet.URL]; ok {
-				return reuse.Dial(network, localAddr, addr)
-			} else {
-				return net.Dial(network, addr)
-			}
-		},
+		MaxConnsPerHost: 1, // to use the same connection per host throughout an iteration
 	}
 
 	tr.DisableKeepAlives = false
@@ -486,19 +477,10 @@ func (h *HttpRequester) initTransport(hostPortMap map[string]string) *http.Trans
 	return tr
 }
 
-func (h *HttpRequester) updateTransport(tr *http.Transport, hostPortMap map[string]string) {
+func (h *HttpRequester) updateTransport(tr *http.Transport) {
 	tr.TLSClientConfig = h.initTLSConfig()
 	tr.Proxy = http.ProxyURL(h.proxyAddr)
 
-	// TODO check
-	tr.Dial = func(network, addr string) (net.Conn, error) {
-		if localAddr, ok := hostPortMap[h.packet.URL]; ok {
-			return reuse.Dial(network, localAddr, addr)
-		} else {
-			return net.Dial(network, addr)
-		}
-	}
-
 	tr.DisableKeepAlives = false
 	if val, ok := h.packet.Custom["keep-alive"]; ok {
 		tr.DisableKeepAlives = !val.(bool)
@@ -572,7 +554,7 @@ func (h *HttpRequester) Type() string {
 	return "HTTP"
 }
 
-func newTrace(duration *duration, proxyAddr *url.URL, reqUrl string, hostPortMap map[string]string) *httptrace.ClientTrace {
+func newTrace(duration *duration, proxyAddr *url.URL) *httptrace.ClientTrace {
 	var dnsStart, connStart, tlsStart, reqStart, serverProcessStart time.Time
 
 	// According to the doc in the trace.go;
@@ -643,7 +625,6 @@ func newTrace(duration *duration, proxyAddr *url.URL, reqUrl string, hostPortMap
 				reqStart = time.Now()
 			}
 			m.Unlock()
-			hostPortMap[reqUrl] = connInfo.Conn.LocalAddr().String()
 		},
 		WroteRequest: func(w httptrace.WroteRequestInfo) {
 			m.Lock()
diff --git a/core/scenario/service.go b/core/scenario/service.go
index 237c2e70..fea4e328 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -46,8 +46,7 @@ type ScenarioService struct {
 	// Each scenarioItem has a requester
 	clients map[*url.URL][]scenarioItemRequester
 
-	cPool  *clientPool
-	client *http.Client
+	cPool *clientPool
 
 	scenario types.Scenario
 	ctx      context.Context
@@ -93,15 +92,13 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 	vi.Init()
 	s.ei = vi
 
-	// initialClientCount := opts.MaxConcurrentIterCount
-	// if !opts.ConnectionReuse {
-	// 	// TODO: timeout and buffer
-	// 	initialClientCount = opts.IterationCount
-	// }
-	// maxClientCount := opts.IterationCount
-	// s.cPool, err = NewClientPool(initialClientCount, maxClientCount, func() *http.Client { return &http.Client{} })
-
-	s.client = &http.Client{}
+	initialClientCount := opts.MaxConcurrentIterCount
+	if !opts.ConnectionReuse {
+		// TODO: timeout and buffer
+		initialClientCount = opts.IterationCount
+	}
+	maxClientCount := opts.IterationCount
+	s.cPool, err = NewClientPool(initialClientCount, maxClientCount, func() *http.Client { return &http.Client{} })
 
 	return
 }
@@ -132,15 +129,13 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 	s.enrichEnvFromData(envs)
 	atomic.AddInt64(&s.iterIndex, 1)
 
-	// client := s.cPool.Get()
-
-	urlPortMap := make(map[string]string)
+	client := s.cPool.Get()
 	for _, sr := range requesters {
 		var res *types.ScenarioStepResult
 		switch sr.requester.Type() {
 		case "HTTP":
 			httpRequester := sr.requester.(requester.HttpRequesterI)
-			res = httpRequester.Send(s.client, envs, urlPortMap) // TODO
+			res = httpRequester.Send(client, envs)
 		default:
 			res = &types.ScenarioStepResult{Err: types.RequestError{Type: fmt.Sprintf("type not defined: %s", sr.requester.Type())}}
 		}
@@ -161,7 +156,7 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 
 		enrichEnvFromPrevStep(envs, res.ExtractedEnvs)
 	}
-	// s.cPool.Put(client)
+	s.cPool.Put(client)
 	return
 }
 
diff --git a/go.mod b/go.mod
index 2d3a60b2..d7da8751 100644
--- a/go.mod
+++ b/go.mod
@@ -21,7 +21,6 @@ require (
 	github.com/go-ole/go-ole v1.2.6 // indirect
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
 	github.com/jaswdr/faker v1.10.2 // indirect
-	github.com/libp2p/go-reuseport v0.2.0 // indirect
 	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
 	github.com/mattn/go-isatty v0.0.14 // indirect
 	github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c // indirect
diff --git a/go.sum b/go.sum
index aa90e953..ffeba571 100644
--- a/go.sum
+++ b/go.sum
@@ -24,8 +24,6 @@ github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/jaswdr/faker v1.10.2 h1:GK03wuDqa8V6BE+2VRr3DJ/G4T0iUDCzVoBCj5TM4b8=
 github.com/jaswdr/faker v1.10.2/go.mod h1:x7ZlyB1AZqwqKZgyQlnqEG8FDptmHlncA5u2zY/yi6w=
-github.com/libp2p/go-reuseport v0.2.0 h1:18PRvIMlpY6ZK85nIAicSBuXXvrYoSw3dsBAR7zc560=
-github.com/libp2p/go-reuseport v0.2.0/go.mod h1:bvVho6eLMm6Bz5hmU0LYN3ixd3nPPvtIlaURZZgOY4k=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 h1:6E+4a0GO5zZEnZ81pIr0yLvtUWk2if982qA3F3QD6H4=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0/go.mod h1:zJYVVT2jmtg6P3p1VtQj7WsuWi/y4VnjVBn7F8KPB3I=
 github.com/mattn/go-colorable v0.1.9/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=

From c2340749e938674150c2617e19f0e8c0695cbb48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 12:37:03 +0300
Subject: [PATCH 18/32] pool done

---
 core/scenario/service.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/scenario/service.go b/core/scenario/service.go
index fea4e328..6fa77cab 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -196,7 +196,7 @@ func (s *ScenarioService) Done() {
 		}
 	}
 
-	// s.cPool.Done()
+	s.cPool.Done()
 }
 
 func (s *ScenarioService) getOrCreateRequesters(proxy *url.URL) (requesters []scenarioItemRequester, err error) {

From 6df492cdfa8656b5ff03ad0f68a1e09f2dc45c79 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 12:52:31 +0300
Subject: [PATCH 19/32] use runtime goexit for defer calls to run in benchmark

---
 main_benchmark_test.go | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/main_benchmark_test.go b/main_benchmark_test.go
index ff340795..e4b26011 100644
--- a/main_benchmark_test.go
+++ b/main_benchmark_test.go
@@ -28,6 +28,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"runtime"
 	"runtime/pprof"
 	"runtime/trace"
 	"strconv"
@@ -124,18 +125,22 @@ func BenchmarkEngines(t *testing.B) {
 		i, _ := strconv.Atoi(index)
 		conf := table[i]
 		outSuffix := ".out"
+		var err error
+
 		// child proc
+		var cpuProfFile, memProfFile, traceFile *os.File
 		if *cpuprofile != "" {
-			f, err := os.Create(fmt.Sprintf("%s_cpuprof_%s.out", strings.TrimSuffix(*cpuprofile, outSuffix), conf.name))
+			cpuProfFile, err = os.Create(fmt.Sprintf("%s_cpuprof_%s.out", strings.TrimSuffix(*cpuprofile, outSuffix), conf.name))
 			if err != nil {
 				log.Fatal(err)
 			}
-			pprof.StartCPUProfile(f)
+			pprof.StartCPUProfile(cpuProfFile)
+			defer cpuProfFile.Close()
 			defer pprof.StopCPUProfile()
 		}
 
 		if *memprofile != "" { // get memory profile at execution finish
-			memProfFile, err := os.Create(fmt.Sprintf("%s_memprof_%s.out", strings.TrimSuffix(*memprofile, outSuffix),
+			memProfFile, err = os.Create(fmt.Sprintf("%s_memprof_%s.out", strings.TrimSuffix(*memprofile, outSuffix),
 				conf.name))
 			if err != nil {
 				log.Fatal("could not create memory profile: ", err)
@@ -150,17 +155,17 @@ func BenchmarkEngines(t *testing.B) {
 		}
 
 		if *keepTrace != "" {
-			f, err := os.Create(fmt.Sprintf("%s_trace_%s.out", strings.TrimSuffix(*keepTrace, outSuffix), conf.name))
+			traceFile, err = os.Create(fmt.Sprintf("%s_trace_%s.out", strings.TrimSuffix(*keepTrace, outSuffix), conf.name))
 			if err != nil {
 				log.Fatalf("failed to create trace output file: %v", err)
 			}
 			defer func() {
-				if err := f.Close(); err != nil {
+				if err := traceFile.Close(); err != nil {
 					log.Fatalf("failed to close trace file: %v", err)
 				}
 			}()
 
-			if err := trace.Start(f); err != nil {
+			if err := trace.Start(traceFile); err != nil {
 				log.Fatalf("failed to start trace: %v", err)
 			}
 			defer trace.Stop()
@@ -215,7 +220,7 @@ func BenchmarkEngines(t *testing.B) {
 		})
 
 		if !success {
-			os.Exit(1)
+			runtime.Goexit()
 		}
 	}
 }

From 71f494615306765084f896d49a23375a07e52219 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 16:17:32 +0300
Subject: [PATCH 20/32] add engine modes

---
 config/json.go                  | 36 ++++++++++++-------------
 config/json_test.go             | 36 ++++++++++++-------------
 core/engine.go                  |  2 +-
 core/scenario/client_pool.go    |  1 -
 core/scenario/requester/base.go |  2 +-
 core/scenario/requester/http.go | 38 +++++++++++++++++++-------
 core/scenario/service.go        | 48 ++++++++++++++++++++++++---------
 core/types/hammer.go            | 11 +++++++-
 8 files changed, 111 insertions(+), 63 deletions(-)

diff --git a/config/json.go b/config/json.go
index df62a70b..bcf0dea2 100644
--- a/config/json.go
+++ b/config/json.go
@@ -144,28 +144,28 @@ func (c *CsvConf) UnmarshalJSON(data []byte) error {
 }
 
 type JsonReader struct {
-	ReqCount        *int                   `json:"request_count"`
-	IterCount       *int                   `json:"iteration_count"`
-	LoadType        string                 `json:"load_type"`
-	Duration        int                    `json:"duration"`
-	TimeRunCount    timeRunCount           `json:"manual_load"`
-	Steps           []step                 `json:"steps"`
-	Output          string                 `json:"output"`
-	Proxy           string                 `json:"proxy"`
-	Envs            map[string]interface{} `json:"env"`
-	Data            map[string]CsvConf     `json:"data"`
-	Debug           bool                   `json:"debug"`
-	SamplingRate    *int                   `json:"sampling_rate"`
-	ConnectionReuse bool                   `json:"connection_reuse"`
+	ReqCount     *int                   `json:"request_count"`
+	IterCount    *int                   `json:"iteration_count"`
+	LoadType     string                 `json:"load_type"`
+	Duration     int                    `json:"duration"`
+	TimeRunCount timeRunCount           `json:"manual_load"`
+	Steps        []step                 `json:"steps"`
+	Output       string                 `json:"output"`
+	Proxy        string                 `json:"proxy"`
+	Envs         map[string]interface{} `json:"env"`
+	Data         map[string]CsvConf     `json:"data"`
+	Debug        bool                   `json:"debug"`
+	SamplingRate *int                   `json:"sampling_rate"`
+	EngineMode   string                 `json:"engine_mode"`
 }
 
 func (j *JsonReader) UnmarshalJSON(data []byte) error {
 	type jsonReaderAlias JsonReader
 	defaultFields := &jsonReaderAlias{
-		LoadType:        types.DefaultLoadType,
-		Duration:        types.DefaultDuration,
-		Output:          types.DefaultOutputType,
-		ConnectionReuse: true,
+		LoadType:   types.DefaultLoadType,
+		Duration:   types.DefaultDuration,
+		Output:     types.DefaultOutputType,
+		EngineMode: types.EngineModeDdosify,
 	}
 
 	err := json.Unmarshal(data, defaultFields)
@@ -277,7 +277,7 @@ func (j *JsonReader) CreateHammer() (h types.Hammer, err error) {
 		ReportDestination: j.Output,
 		Debug:             j.Debug,
 		SamplingRate:      samplingRate,
-		ConnectionReuse:   j.ConnectionReuse,
+		EngineMode:        j.EngineMode,
 	}
 	return
 }
diff --git a/config/json_test.go b/config/json_test.go
index 687aed88..dbe4aa1b 100644
--- a/config/json_test.go
+++ b/config/json_test.go
@@ -55,8 +55,8 @@ func TestCreateHammerDefaultValues(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -111,8 +111,8 @@ func TestCreateHammer(t *testing.T) {
 			Strategy: "single",
 			Addr:     addr,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -167,8 +167,8 @@ func TestCreateHammerWithIterationCountInsteadOfReqCount(t *testing.T) {
 			Strategy: "single",
 			Addr:     addr,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -226,8 +226,8 @@ func TestCreateHammerWithIterationCountOverridesReqCount(t *testing.T) {
 			Strategy: "single",
 			Addr:     addr,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -262,8 +262,8 @@ func TestCreateHammerManualLoad(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -298,8 +298,8 @@ func TestCreateHammerManualLoadOverrideOthers(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -557,8 +557,8 @@ func TestCreateHammerTLSWithOnlyCertPath(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -603,8 +603,8 @@ func TestCreateHammerTLSWithOnlyKeyPath(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
@@ -640,8 +640,8 @@ func TestCreateHammerTLSWithWithEmptyPath(t *testing.T) {
 		Proxy: proxy.Proxy{
 			Strategy: proxy.ProxyTypeSingle,
 		},
-		SamplingRate:    types.DefaultSamplingCount,
-		ConnectionReuse: true,
+		SamplingRate: types.DefaultSamplingCount,
+		EngineMode:   types.EngineModeDdosify,
 	}
 
 	h, err := jsonReader.CreateHammer()
diff --git a/core/engine.go b/core/engine.go
index 35f00f72..581225ae 100644
--- a/core/engine.go
+++ b/core/engine.go
@@ -100,7 +100,7 @@ func (e *engine) Init() (err error) {
 		Debug:                  e.hammer.Debug,
 		IterationCount:         e.hammer.IterationCount,
 		MaxConcurrentIterCount: e.getMaxConcurrentIterCount(),
-		ConnectionReuse:        e.hammer.ConnectionReuse,
+		EngineMode:             e.hammer.EngineMode,
 	}); err != nil {
 		return
 	}
diff --git a/core/scenario/client_pool.go b/core/scenario/client_pool.go
index 4892bc5e..16ba778c 100644
--- a/core/scenario/client_pool.go
+++ b/core/scenario/client_pool.go
@@ -9,7 +9,6 @@ type clientPool struct {
 	// storage for our http.Clients
 	clients chan *http.Client
 	factory Factory
-	N       int
 }
 
 // Factory is a function to create new connections.
diff --git a/core/scenario/requester/base.go b/core/scenario/requester/base.go
index 25547bac..57fff9e8 100644
--- a/core/scenario/requester/base.go
+++ b/core/scenario/requester/base.go
@@ -38,7 +38,7 @@ type Requester interface {
 
 type HttpRequesterI interface {
 	Init(ctx context.Context, ss types.ScenarioStep, url *url.URL, debug bool, ei *injection.EnvironmentInjector) error
-	Send(client *http.Client, envs map[string]interface{}) *types.ScenarioStepResult
+	Send(client *http.Client, envs map[string]interface{}) *types.ScenarioStepResult // should use its own client if client is nil
 }
 
 // NewRequester is the factory method of the Requester.
diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index 861f65de..7fcc027c 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -50,6 +50,7 @@ type HttpRequester struct {
 	ctx                  context.Context
 	proxyAddr            *url.URL
 	packet               types.ScenarioStep
+	client               *http.Client
 	request              *http.Request
 	ei                   *injection.EnvironmentInjector
 	containsDynamicField map[string]bool
@@ -72,6 +73,21 @@ func (h *HttpRequester) Init(ctx context.Context, s types.ScenarioStep, proxyAdd
 	h.dynamicRgx = regexp.MustCompile(regex.DynamicVariableRegex)
 	h.envRgx = regexp.MustCompile(regex.EnvironmentVariableRegex)
 
+	// Transport segment
+	tr := h.initTransport()
+	tr.MaxConnsPerHost = 60000
+
+	// http client
+	h.client = &http.Client{Transport: tr, Timeout: time.Duration(h.packet.Timeout) * time.Second}
+	if val, ok := h.packet.Custom["disable-redirect"]; ok {
+		val := val.(bool)
+		if val {
+			h.client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
+				return http.ErrUseLastResponse
+			}
+		}
+	}
+
 	// Request instance
 	err = h.initRequestInstance()
 	if err != nil {
@@ -148,8 +164,7 @@ func (h *HttpRequester) Done() {
 	// When the Job is finished, we have to Close idle connections to prevent sockets to lock in at the TIME_WAIT state.
 	// Otherwise, the next job can't use these sockets because they are reserved for the current target host.
 
-	// TODO
-	// h.client.CloseIdleConnections()
+	h.client.CloseIdleConnections()
 }
 
 func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (res *types.ScenarioStepResult) {
@@ -173,14 +188,18 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (
 	}
 
 	if client == nil {
-		client = &http.Client{}
-	}
-
-	// Transport segment
-	if client.Transport == nil {
-		client.Transport = h.initTransport()
+		// engine mode is 'ddosify'
+		// if passed client is nil , use requesters client that is dedicated to one step, thereby one transport
+		client = h.client
 	} else {
-		h.updateTransport(client.Transport.(*http.Transport))
+		// engine mode is 'distinct-user' or 'repeated-user'
+		// passed client is used for multiple steps throughout an iteration, update transport
+		if client.Transport == nil {
+			client.Transport = h.initTransport()
+			client.Transport.(*http.Transport).MaxConnsPerHost = 1 // use same connection per host throughout an iteration
+		} else {
+			h.updateTransport(client.Transport.(*http.Transport))
+		}
 	}
 
 	// http client
@@ -458,7 +477,6 @@ func (h *HttpRequester) initTransport() *http.Transport {
 	tr := &http.Transport{
 		TLSClientConfig: h.initTLSConfig(),
 		Proxy:           http.ProxyURL(h.proxyAddr),
-		MaxConnsPerHost: 1, // to use the same connection per host throughout an iteration
 	}
 
 	tr.DisableKeepAlives = false
diff --git a/core/scenario/service.go b/core/scenario/service.go
index 6fa77cab..f26dfff9 100644
--- a/core/scenario/service.go
+++ b/core/scenario/service.go
@@ -53,8 +53,10 @@ type ScenarioService struct {
 
 	clientMutex sync.Mutex
 	debug       bool
-	ei          *injection.EnvironmentInjector
-	iterIndex   int64
+	engineMode  string
+
+	ei        *injection.EnvironmentInjector
+	iterIndex int64
 }
 
 // NewScenarioService is the constructor of the ScenarioService.
@@ -66,7 +68,7 @@ type ScenarioOpts struct {
 	Debug                  bool
 	IterationCount         int
 	MaxConcurrentIterCount int
-	ConnectionReuse        bool
+	EngineMode             string
 }
 
 // Init initializes the ScenarioService.clients with the given types.Scenario and proxies.
@@ -91,14 +93,19 @@ func (s *ScenarioService) Init(ctx context.Context, scenario types.Scenario,
 	vi := &injection.EnvironmentInjector{}
 	vi.Init()
 	s.ei = vi
-
-	initialClientCount := opts.MaxConcurrentIterCount
-	if !opts.ConnectionReuse {
-		// TODO: timeout and buffer
-		initialClientCount = opts.IterationCount
+	s.engineMode = opts.EngineMode
+
+	if s.engineInUserMode() {
+		// create client pool
+		var initialCount int
+		if s.engineMode == types.EngineModeRepeatedUser {
+			initialCount = opts.MaxConcurrentIterCount
+		} else if s.engineMode == types.EngineModeDistinctUser {
+			initialCount = opts.IterationCount
+		}
+		s.cPool, err = NewClientPool(initialCount, opts.IterationCount, func() *http.Client { return &http.Client{} })
 	}
-	maxClientCount := opts.IterationCount
-	s.cPool, err = NewClientPool(initialClientCount, maxClientCount, func() *http.Client { return &http.Client{} })
+	// s.cPool will be nil otherwise
 
 	return
 }
@@ -129,7 +136,13 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 	s.enrichEnvFromData(envs)
 	atomic.AddInt64(&s.iterIndex, 1)
 
-	client := s.cPool.Get()
+	var client *http.Client
+	if s.engineInUserMode() {
+		// get client from pool
+		client = s.cPool.Get()
+		defer s.cPool.Put(client)
+	}
+
 	for _, sr := range requesters {
 		var res *types.ScenarioStepResult
 		switch sr.requester.Type() {
@@ -156,7 +169,7 @@ func (s *ScenarioService) Do(proxy *url.URL, startTime time.Time) (
 
 		enrichEnvFromPrevStep(envs, res.ExtractedEnvs)
 	}
-	s.cPool.Put(client)
+
 	return
 }
 
@@ -166,6 +179,13 @@ func enrichEnvFromPrevStep(m1 map[string]interface{}, m2 map[string]interface{})
 	}
 }
 
+func (s *ScenarioService) engineInUserMode() bool {
+	if s.engineMode == types.EngineModeDistinctUser || s.engineMode == types.EngineModeRepeatedUser {
+		return true
+	}
+	return false
+}
+
 func (s *ScenarioService) enrichEnvFromData(envs map[string]interface{}) {
 	var row map[string]interface{}
 	sb := strings.Builder{}
@@ -196,7 +216,9 @@ func (s *ScenarioService) Done() {
 		}
 	}
 
-	s.cPool.Done()
+	if s.cPool != nil {
+		s.cPool.Done()
+	}
 }
 
 func (s *ScenarioService) getOrCreateRequesters(proxy *url.URL) (requesters []scenarioItemRequester, err error) {
diff --git a/core/types/hammer.go b/core/types/hammer.go
index 86417665..be68c051 100644
--- a/core/types/hammer.go
+++ b/core/types/hammer.go
@@ -35,6 +35,11 @@ const (
 	LoadTypeIncremental = "incremental"
 	LoadTypeWaved       = "waved"
 
+	// EngineModes
+	EngineModeDistinctUser = "distinct-user"
+	EngineModeRepeatedUser = "repeated-user"
+	EngineModeDdosify      = "ddosify"
+
 	// Default Values
 	DefaultIterCount     = 100
 	DefaultLoadType      = LoadTypeLinear
@@ -46,6 +51,7 @@ const (
 )
 
 var loadTypes = [...]string{LoadTypeLinear, LoadTypeIncremental, LoadTypeWaved}
+var engineModes = [...]string{EngineModeDdosify, EngineModeDistinctUser, EngineModeRepeatedUser}
 
 // TimeRunCount is the data structure to store manual load type data.
 type TimeRunCount []struct {
@@ -87,7 +93,7 @@ type Hammer struct {
 	SamplingRate int
 
 	// Connection reuse
-	ConnectionReuse bool
+	EngineMode string
 }
 
 // Validate validates attack metadata and executes the validation methods of the services.
@@ -101,6 +107,9 @@ func (h *Hammer) Validate() error {
 	if h.LoadType != "" && !util.StringInSlice(h.LoadType, loadTypes[:]) {
 		return fmt.Errorf("unsupported LoadType: %s", h.LoadType)
 	}
+	if h.EngineMode != "" && !util.StringInSlice(h.EngineMode, engineModes[:]) {
+		return fmt.Errorf("unsupported EngineMode: %s", h.EngineMode)
+	}
 
 	if len(h.TimeRunCountMap) > 0 {
 		for _, t := range h.TimeRunCountMap {

From 01202603e95dcf7a7d85fe055b6d0f9a3155a4e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 16:29:36 +0300
Subject: [PATCH 21/32] fix unnecessary race

---
 core/scenario/requester/http.go | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index 7fcc027c..04c25a9a 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -202,17 +202,6 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (
 		}
 	}
 
-	// http client
-	client.Timeout = time.Duration(h.packet.Timeout) * time.Second
-	if val, ok := h.packet.Custom["disable-redirect"]; ok {
-		val := val.(bool)
-		if val {
-			client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
-				return http.ErrUseLastResponse
-			}
-		}
-	}
-
 	durations := &duration{}
 	trace := newTrace(durations, h.proxyAddr)
 	httpReq, err := h.prepareReq(usableVars, trace)

From a9432e7ae202e9c85ad2ec7a61c87755275a7454 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 16:37:09 +0300
Subject: [PATCH 22/32] fix test

---
 core/scenario/requester/http_test.go | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/core/scenario/requester/http_test.go b/core/scenario/requester/http_test.go
index 16e9627a..c48e899e 100644
--- a/core/scenario/requester/http_test.go
+++ b/core/scenario/requester/http_test.go
@@ -158,10 +158,8 @@ func TestInitClient(t *testing.T) {
 		tf := func(t *testing.T) {
 			h := &HttpRequester{}
 			h.Init(test.ctx, test.scenarioItem, test.proxy, false, nil)
-			client := &http.Client{}
-			h.Send(client, map[string]interface{}{})
 
-			transport := client.Transport.(*http.Transport)
+			transport := h.client.Transport.(*http.Transport)
 			tls := transport.TLSClientConfig
 
 			// TLS Assert (Also check HTTP2 vs HTTP)
@@ -189,11 +187,11 @@ func TestInitClient(t *testing.T) {
 			}
 
 			// Client Assert
-			if test.client.Timeout != client.Timeout {
-				t.Errorf("Timeout Expected %v, Found %v", test.client.Timeout, client.Timeout)
+			if test.client.Timeout != h.client.Timeout {
+				t.Errorf("Timeout Expected %v, Found %v", test.client.Timeout, h.client.Timeout)
 			}
 
-			crFunc := client.CheckRedirect == nil
+			crFunc := h.client.CheckRedirect == nil
 			expectedCRFunc := test.client.CheckRedirect == nil
 			if expectedCRFunc != crFunc {
 				t.Errorf("CheckRedirect Expected %v, Found %v", expectedCRFunc, crFunc)

From 7889ff89a9094356715f212802703becee38143a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 16:51:33 +0300
Subject: [PATCH 23/32] run benchmarks on repeated-user mode

---
 config/config_testdata/benchmark/config_correlation_load_1.json | 1 +
 config/config_testdata/benchmark/config_correlation_load_2.json | 1 +
 config/config_testdata/benchmark/config_correlation_load_3.json | 1 +
 config/config_testdata/benchmark/config_correlation_load_4.json | 2 ++
 config/config_testdata/benchmark/config_correlation_load_5.json | 2 ++
 5 files changed, 7 insertions(+)

diff --git a/config/config_testdata/benchmark/config_correlation_load_1.json b/config/config_testdata/benchmark/config_correlation_load_1.json
index 375adf37..3a959f8e 100644
--- a/config/config_testdata/benchmark/config_correlation_load_1.json
+++ b/config/config_testdata/benchmark/config_correlation_load_1.json
@@ -1,5 +1,6 @@
 {
     "iteration_count": 100,
+    "engine_mode": "repeated-user",
     "load_type": "waved",
     "duration": 10,
     "steps": [
diff --git a/config/config_testdata/benchmark/config_correlation_load_2.json b/config/config_testdata/benchmark/config_correlation_load_2.json
index 785776dd..8ccf276c 100644
--- a/config/config_testdata/benchmark/config_correlation_load_2.json
+++ b/config/config_testdata/benchmark/config_correlation_load_2.json
@@ -1,6 +1,7 @@
 {
     "iteration_count": 1000,
     "load_type": "waved",
+    "engine_mode": "repeated-user",
     "duration": 10,
     "steps": [
             {
diff --git a/config/config_testdata/benchmark/config_correlation_load_3.json b/config/config_testdata/benchmark/config_correlation_load_3.json
index c4be1283..d16873a1 100644
--- a/config/config_testdata/benchmark/config_correlation_load_3.json
+++ b/config/config_testdata/benchmark/config_correlation_load_3.json
@@ -1,6 +1,7 @@
 {
     "iteration_count": 5000,
     "load_type": "waved",
+    "engine_mode": "repeated-user",
     "duration": 10,
     "steps": [
             {
diff --git a/config/config_testdata/benchmark/config_correlation_load_4.json b/config/config_testdata/benchmark/config_correlation_load_4.json
index ca1fbb0f..4b660e93 100644
--- a/config/config_testdata/benchmark/config_correlation_load_4.json
+++ b/config/config_testdata/benchmark/config_correlation_load_4.json
@@ -1,6 +1,8 @@
 {
     "iteration_count": 10000,
     "load_type": "waved",
+    "engine_mode": "repeated-user",
+
     "duration": 10,
     "steps": [
             {
diff --git a/config/config_testdata/benchmark/config_correlation_load_5.json b/config/config_testdata/benchmark/config_correlation_load_5.json
index c38f24d2..7919b1b5 100644
--- a/config/config_testdata/benchmark/config_correlation_load_5.json
+++ b/config/config_testdata/benchmark/config_correlation_load_5.json
@@ -1,6 +1,8 @@
 {
     "iteration_count": 20000,
     "load_type": "waved",
+    "engine_mode": "repeated-user",
+
     "duration": 10,
     "steps": [
             {

From cefcca99cfa00029956de3c22692074025a14354 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 17:43:30 +0300
Subject: [PATCH 24/32] run benchmarks on ddosify mode

---
 config/config_testdata/benchmark/config_correlation_load_1.json | 2 +-
 config/config_testdata/benchmark/config_correlation_load_2.json | 2 +-
 config/config_testdata/benchmark/config_correlation_load_3.json | 2 +-
 config/config_testdata/benchmark/config_correlation_load_4.json | 2 +-
 config/config_testdata/benchmark/config_correlation_load_5.json | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/config/config_testdata/benchmark/config_correlation_load_1.json b/config/config_testdata/benchmark/config_correlation_load_1.json
index 3a959f8e..16984586 100644
--- a/config/config_testdata/benchmark/config_correlation_load_1.json
+++ b/config/config_testdata/benchmark/config_correlation_load_1.json
@@ -1,6 +1,6 @@
 {
     "iteration_count": 100,
-    "engine_mode": "repeated-user",
+    "engine_mode": "ddosify",
     "load_type": "waved",
     "duration": 10,
     "steps": [
diff --git a/config/config_testdata/benchmark/config_correlation_load_2.json b/config/config_testdata/benchmark/config_correlation_load_2.json
index 8ccf276c..15b4c8b2 100644
--- a/config/config_testdata/benchmark/config_correlation_load_2.json
+++ b/config/config_testdata/benchmark/config_correlation_load_2.json
@@ -1,7 +1,7 @@
 {
     "iteration_count": 1000,
     "load_type": "waved",
-    "engine_mode": "repeated-user",
+    "engine_mode": "ddosify",
     "duration": 10,
     "steps": [
             {
diff --git a/config/config_testdata/benchmark/config_correlation_load_3.json b/config/config_testdata/benchmark/config_correlation_load_3.json
index d16873a1..0e9343ec 100644
--- a/config/config_testdata/benchmark/config_correlation_load_3.json
+++ b/config/config_testdata/benchmark/config_correlation_load_3.json
@@ -1,7 +1,7 @@
 {
     "iteration_count": 5000,
     "load_type": "waved",
-    "engine_mode": "repeated-user",
+    "engine_mode": "ddosify",
     "duration": 10,
     "steps": [
             {
diff --git a/config/config_testdata/benchmark/config_correlation_load_4.json b/config/config_testdata/benchmark/config_correlation_load_4.json
index 4b660e93..f386f549 100644
--- a/config/config_testdata/benchmark/config_correlation_load_4.json
+++ b/config/config_testdata/benchmark/config_correlation_load_4.json
@@ -1,7 +1,7 @@
 {
     "iteration_count": 10000,
     "load_type": "waved",
-    "engine_mode": "repeated-user",
+    "engine_mode": "ddosify",
 
     "duration": 10,
     "steps": [
diff --git a/config/config_testdata/benchmark/config_correlation_load_5.json b/config/config_testdata/benchmark/config_correlation_load_5.json
index 7919b1b5..d3179055 100644
--- a/config/config_testdata/benchmark/config_correlation_load_5.json
+++ b/config/config_testdata/benchmark/config_correlation_load_5.json
@@ -1,7 +1,7 @@
 {
     "iteration_count": 20000,
     "load_type": "waved",
-    "engine_mode": "repeated-user",
+    "engine_mode": "ddosify",
 
     "duration": 10,
     "steps": [

From b23afa58fb7966c69e371bc217f5974fee971ee6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 17:45:22 +0300
Subject: [PATCH 25/32] set maxIdleConns to unlimited

---
 core/scenario/requester/http.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index 04c25a9a..ad4772c3 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -76,6 +76,7 @@ func (h *HttpRequester) Init(ctx context.Context, s types.ScenarioStep, proxyAdd
 	// Transport segment
 	tr := h.initTransport()
 	tr.MaxConnsPerHost = 60000
+	tr.MaxIdleConns = 0
 
 	// http client
 	h.client = &http.Client{Transport: tr, Timeout: time.Duration(h.packet.Timeout) * time.Second}

From 5086a65862ab96ff254a9448cabc0ad223ddcb59 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 17 Feb 2023 18:09:19 +0300
Subject: [PATCH 26/32] change maxidle conns per host

---
 core/scenario/requester/http.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index ad4772c3..342685f7 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -75,7 +75,7 @@ func (h *HttpRequester) Init(ctx context.Context, s types.ScenarioStep, proxyAdd
 
 	// Transport segment
 	tr := h.initTransport()
-	tr.MaxConnsPerHost = 60000
+	tr.MaxIdleConnsPerHost = 60000
 	tr.MaxIdleConns = 0
 
 	// http client

From 7816b7b70bad24eec941366df0fb1a98697b2455 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Mon, 20 Feb 2023 15:41:39 +0300
Subject: [PATCH 27/32] put headers added by client to step result

---
 core/scenario/requester/http.go      | 24 +++++++++++++++++++++---
 core/scenario/requester/http_test.go | 11 +++++++----
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index 342685f7..ca5d59bb 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -204,7 +204,8 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (
 	}
 
 	durations := &duration{}
-	trace := newTrace(durations, h.proxyAddr)
+	headersAddedByClient := make(map[string][]string)
+	trace := newTrace(durations, h.proxyAddr, headersAddedByClient)
 	httpReq, err := h.prepareReq(usableVars, trace)
 
 	if err != nil { // could not prepare req
@@ -291,7 +292,7 @@ func (h *HttpRequester) Send(client *http.Client, envs map[string]interface{}) (
 
 		Url:         httpReq.URL.String(),
 		Method:      httpReq.Method,
-		ReqHeaders:  httpReq.Header,
+		ReqHeaders:  concatHeaders(httpReq.Header, headersAddedByClient),
 		ReqBody:     copiedReqBody.Bytes(),
 		RespHeaders: respHeaders,
 		RespBody:    respBody,
@@ -334,6 +335,20 @@ func concatEnvs(envs1, envs2 map[string]interface{}) map[string]interface{} {
 	return total
 }
 
+func concatHeaders(envs1, envs2 map[string][]string) map[string][]string {
+	total := make(map[string][]string)
+
+	for k, v := range envs1 {
+		total[k] = v
+	}
+
+	for k, v := range envs2 {
+		total[k] = v
+	}
+
+	return total
+}
+
 func (h *HttpRequester) prepareReq(envs map[string]interface{}, trace *httptrace.ClientTrace) (*http.Request, error) {
 	re := regexp.MustCompile(regex.DynamicVariableRegex)
 	httpReq := h.request.Clone(h.ctx)
@@ -562,7 +577,7 @@ func (h *HttpRequester) Type() string {
 	return "HTTP"
 }
 
-func newTrace(duration *duration, proxyAddr *url.URL) *httptrace.ClientTrace {
+func newTrace(duration *duration, proxyAddr *url.URL, headersByClient map[string][]string) *httptrace.ClientTrace {
 	var dnsStart, connStart, tlsStart, reqStart, serverProcessStart time.Time
 
 	// According to the doc in the trace.go;
@@ -649,6 +664,9 @@ func newTrace(duration *duration, proxyAddr *url.URL) *httptrace.ClientTrace {
 			duration.setResStartTime(time.Now())
 			m.Unlock()
 		},
+		WroteHeaderField: func(key string, value []string) {
+			headersByClient[key] = value
+		},
 	}
 }
 
diff --git a/core/scenario/requester/http_test.go b/core/scenario/requester/http_test.go
index c48e899e..d1ee92a7 100644
--- a/core/scenario/requester/http_test.go
+++ b/core/scenario/requester/http_test.go
@@ -379,11 +379,14 @@ func TestSendOnDebugModePopulatesDebugInfo(t *testing.T) {
 			t.Errorf("RequestBody Expected %#v, Found: \n%#v", expectedRequestBody,
 				res.ReqBody)
 		}
-		if !reflect.DeepEqual(expectedRequestHeaders, res.ReqHeaders) {
-			t.Errorf("RequestHeaders Expected %#v, Found: \n%#v", expectedRequestHeaders,
-				res.ReqHeaders)
-		}
 
+		// stepResult has default request headers added by go client
+		for expKey, expVal := range expectedRequestHeaders {
+			if !reflect.DeepEqual(expVal, res.ReqHeaders.Values(expKey)) {
+				t.Errorf("RequestHeaders Expected %#v, Found: \n%#v", expectedRequestHeaders,
+					res.ReqHeaders)
+			}
+		}
 	}
 	t.Run("populate-debug-info", tf)
 }

From b9da7d2d587d6481d4ffc77e22e0778f2566c77e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Wed, 22 Feb 2023 10:02:12 +0000
Subject: [PATCH 28/32] add test for engine modes

---
 core/engine_test.go | 154 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)

diff --git a/core/engine_test.go b/core/engine_test.go
index 634d7643..e789fa54 100644
--- a/core/engine_test.go
+++ b/core/engine_test.go
@@ -1772,6 +1772,160 @@ func TestTLSMutualAuthButServerAndClientHasDifferentCerts(t *testing.T) {
 	}
 }
 
+func TestEngineModeUserKeepAlive(t *testing.T) {
+	t.Parallel()
+	// For DistinctUser and RepeatedUser modes
+
+	// Test server
+	clientAddress1 := []string{}
+	clientAddress2 := []string{}
+	var m1 sync.Mutex
+	var m2 sync.Mutex
+
+	firstReqHandler := func(w http.ResponseWriter, r *http.Request) {
+		m1.Lock()
+		defer m1.Unlock()
+
+		clientAddress1 = append(clientAddress1, r.RemoteAddr) // network address that sent the request
+	}
+
+	secondReqHandler := func(w http.ResponseWriter, r *http.Request) {
+		m2.Lock()
+		defer m2.Unlock()
+
+		clientAddress2 = append(clientAddress2, r.RemoteAddr) // network address that sent the request
+	}
+
+	pathFirst := "/first"
+	pathSecond := "/second"
+
+	mux := http.NewServeMux()
+	mux.HandleFunc(pathFirst, firstReqHandler)
+	mux.HandleFunc(pathSecond, secondReqHandler)
+
+	host := httptest.NewServer(mux)
+	defer host.Close()
+
+	// Prepare
+	h := newDummyHammer()
+	h.IterationCount = 2
+	h.Scenario.Steps = make([]types.ScenarioStep, 2)
+	h.Scenario.Steps[0] = types.ScenarioStep{
+		ID:      1,
+		Method:  "GET",
+		URL:     host.URL + pathFirst,
+		Headers: map[string]string{"ID": "1"},
+	}
+	h.Scenario.Steps[1] = types.ScenarioStep{
+		ID:      2,
+		Method:  "GET",
+		URL:     host.URL + pathSecond,
+		Headers: map[string]string{"ID": "2"},
+	}
+
+	// Act
+	h.EngineMode = types.EngineModeDistinctUser
+	e, err := NewEngine(context.TODO(), h)
+	if err != nil {
+		t.Errorf("TestEngineModeDistinctUserKeepAlive error occurred %v", err)
+	}
+
+	err = e.Init()
+	if err != nil {
+		t.Errorf("TestEngineModeDistinctUserKeepAlive error occurred %v", err)
+	}
+
+	e.Start()
+
+	// same host
+
+	// check first iter
+	if clientAddress1[0] != clientAddress2[0] {
+		t.Errorf("TestEngineModeDistinctUserKeepAlive, same hosts connection should be same throughout iteration")
+	}
+	// check second iter
+	if clientAddress1[1] != clientAddress2[1] {
+		t.Errorf("TestEngineModeDistinctUserKeepAlive, same hosts connection should be same throughout iteration")
+	}
+
+}
+
+func TestEngineModeDdosifyKeepAlive(t *testing.T) {
+	t.Parallel()
+
+	// Test server
+	clientAddress1 := []string{}
+	clientAddress2 := []string{}
+	var m1 sync.Mutex
+	var m2 sync.Mutex
+
+	firstReqHandler := func(w http.ResponseWriter, r *http.Request) {
+		m1.Lock()
+		defer m1.Unlock()
+
+		clientAddress1 = append(clientAddress1, r.RemoteAddr) // network address that sent the request
+	}
+
+	secondReqHandler := func(w http.ResponseWriter, r *http.Request) {
+		m2.Lock()
+		defer m2.Unlock()
+
+		clientAddress2 = append(clientAddress2, r.RemoteAddr) // network address that sent the request
+	}
+
+	pathFirst := "/first"
+	pathSecond := "/second"
+
+	mux := http.NewServeMux()
+	mux.HandleFunc(pathFirst, firstReqHandler)
+	mux.HandleFunc(pathSecond, secondReqHandler)
+
+	host := httptest.NewServer(mux)
+	defer host.Close()
+
+	// Prepare
+	h := newDummyHammer()
+	h.IterationCount = 2
+	h.Scenario.Steps = make([]types.ScenarioStep, 2)
+	h.Scenario.Steps[0] = types.ScenarioStep{
+		ID:      1,
+		Method:  "GET",
+		URL:     host.URL + pathFirst,
+		Headers: map[string]string{"ID": "1"},
+	}
+	h.Scenario.Steps[1] = types.ScenarioStep{
+		ID:      2,
+		Method:  "GET",
+		URL:     host.URL + pathSecond,
+		Headers: map[string]string{"ID": "2"},
+	}
+
+	// Act
+	h.EngineMode = types.EngineModeDdosify
+	e, err := NewEngine(context.TODO(), h)
+	if err != nil {
+		t.Errorf("TestEngineModeDdosifyKeepAlive error occurred %v", err)
+	}
+
+	err = e.Init()
+	if err != nil {
+		t.Errorf("TestEngineModeDdosifyKeepAlive error occurred %v", err)
+	}
+
+	e.Start()
+
+	// same host
+	// in ddosify mode every step has its own client, therefore connections should be different
+	// check first iter
+	if clientAddress1[0] == clientAddress2[0] {
+		t.Errorf("TestEngineModeDistinctUserKeepAlive, ")
+	}
+	// check second iter
+	if clientAddress1[1] == clientAddress2[1] {
+		t.Errorf("TestEngineModeDistinctUserKeepAlive, ")
+	}
+
+}
 func createCertPairFiles(cert string, certKey string) (*os.File, *os.File, error) {
 	certFile, err := os.CreateTemp("", ".pem")
 	if err != nil {

From 1b407ccc108eeed7e3a9f1a0b61d9423feb2eac1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Wed, 22 Feb 2023 11:05:52 +0000
Subject: [PATCH 29/32] engine mode tests

---
 core/engine_test.go | 171 +++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 154 insertions(+), 17 deletions(-)

diff --git a/core/engine_test.go b/core/engine_test.go
index e789fa54..2695465b 100644
--- a/core/engine_test.go
+++ b/core/engine_test.go
@@ -1811,20 +1811,18 @@ func TestEngineModeUserKeepAlive(t *testing.T) {
 	h.IterationCount = 2
 	h.Scenario.Steps = make([]types.ScenarioStep, 2)
 	h.Scenario.Steps[0] = types.ScenarioStep{
-		ID:      1,
-		Method:  "GET",
-		URL:     host.URL + pathFirst,
-		Headers: map[string]string{"ID": "1"},
+		ID:     1,
+		Method: "GET",
+		URL:    host.URL + pathFirst,
 	}
 	h.Scenario.Steps[1] = types.ScenarioStep{
-		ID:      2,
-		Method:  "GET",
-		URL:     host.URL + pathSecond,
-		Headers: map[string]string{"ID": "2"},
+		ID:     2,
+		Method: "GET",
+		URL:    host.URL + pathSecond,
 	}
 
 	// Act
-	h.EngineMode = types.EngineModeDistinctUser
+	h.EngineMode = types.EngineModeRepeatedUser // could have been DistinctUser also
 	e, err := NewEngine(context.TODO(), h)
 	if err != nil {
 		t.Errorf("TestEngineModeDistinctUserKeepAlive error occurred %v", err)
@@ -1850,6 +1848,147 @@ func TestEngineModeUserKeepAlive(t *testing.T) {
 
 }
 
+func TestEngineModeUserKeepAliveDifferentHosts(t *testing.T) {
+	t.Parallel()
+	// For DistinctUser and RepeatedUser modes
+
+	// Test server
+	clientAddress := make(map[string]struct{})
+	var m sync.Mutex
+
+	firstReqHandler := func(w http.ResponseWriter, r *http.Request) {
+		m.Lock()
+		defer m.Unlock()
+		clientAddress[r.RemoteAddr] = struct{}{} // network address that sent the request
+	}
+
+	pathFirst := "/first"
+
+	mux := http.NewServeMux()
+	mux.HandleFunc(pathFirst, firstReqHandler)
+
+	host1 := httptest.NewServer(mux)
+	host2 := httptest.NewServer(mux)
+
+	defer host1.Close()
+	defer host2.Close()
+
+	// Prepare
+	h := newDummyHammer()
+	h.IterationCount = 1
+	h.Scenario.Steps = make([]types.ScenarioStep, 4)
+	h.Scenario.Steps[0] = types.ScenarioStep{
+		ID:     1,
+		Method: "GET",
+		URL:    host1.URL + pathFirst,
+	}
+	h.Scenario.Steps[1] = types.ScenarioStep{
+		ID:     2,
+		Method: "GET",
+		URL:    host1.URL + pathFirst,
+	}
+	h.Scenario.Steps[2] = types.ScenarioStep{
+		ID:     3,
+		Method: "GET",
+		URL:    host2.URL + pathFirst,
+	}
+	h.Scenario.Steps[3] = types.ScenarioStep{
+		ID:     4,
+		Method: "GET",
+		URL:    host2.URL + pathFirst,
+	}
+
+	// Act
+	h.EngineMode = types.EngineModeDistinctUser // could have been RepeatedUser also
+	e, err := NewEngine(context.TODO(), h)
+	if err != nil {
+		t.Errorf("TestEngineModeUserKeepAliveDifferentHosts error occurred %v", err)
+	}
+
+	err = e.Init()
+	if err != nil {
+		t.Errorf("TestEngineModeUserKeepAliveDifferentHosts error occurred %v", err)
+	}
+
+	e.Start()
+
+	// one iteration, two hosts, two connections expected
+	if len(clientAddress) != 2 {
+		t.Errorf("TestEngineModeUserKeepAliveDifferentHosts, expected 2 connections, got : %d", len(clientAddress))
+	}
+}
+
+func TestEngineModeUserKeepAlive_StepsKeepAliveFalse(t *testing.T) {
+	t.Parallel()
+	// For DistinctUser and RepeatedUser modes
+	// Test server
+	clientAddress := make(map[string]struct{})
+	var m sync.Mutex
+
+	firstReqHandler := func(w http.ResponseWriter, r *http.Request) {
+		m.Lock()
+		defer m.Unlock()
+		clientAddress[r.RemoteAddr] = struct{}{} // network address that sent the request
+	}
+
+	pathFirst := "/first"
+
+	mux := http.NewServeMux()
+	mux.HandleFunc(pathFirst, firstReqHandler)
+
+	host1 := httptest.NewServer(mux)
+
+	defer host1.Close()
+
+	// Prepare
+	h := newDummyHammer()
+	h.IterationCount = 1
+	h.Scenario.Steps = make([]types.ScenarioStep, 4)
+	// connection opened by 1 will not be reused
+	h.Scenario.Steps[0] = types.ScenarioStep{
+		ID:     1,
+		Method: "GET",
+		URL:    host1.URL + pathFirst,
+		Custom: map[string]interface{}{"keep-alive": false},
+	}
+	// below will use the connection opened by 2
+	h.Scenario.Steps[1] = types.ScenarioStep{
+		ID:     2,
+		Method: "GET",
+		URL:    host1.URL + pathFirst,
+	}
+	h.Scenario.Steps[2] = types.ScenarioStep{
+		ID:     3,
+		Method: "GET",
+		URL:    host1.URL + pathFirst,
+	}
+	h.Scenario.Steps[3] = types.ScenarioStep{
+		ID:     4,
+		Method: "GET",
+		URL:    host1.URL + pathFirst,
+	}
+
+	// Act
+	h.EngineMode = types.EngineModeDistinctUser
+	e, err := NewEngine(context.TODO(), h)
+	if err != nil {
+		t.Errorf("TestEngineModeUserKeepAliveDifferentHosts error occurred %v", err)
+	}
+
+	err = e.Init()
+	if err != nil {
+		t.Errorf("TestEngineModeUserKeepAliveDifferentHosts error occurred %v", err)
+	}
+
+	e.Start()
+
+	// one iteration, one host, 4 steps, one's keep-alive is false
+	if len(clientAddress) != 2 {
+		t.Errorf("TestEngineModeUserKeepAliveDifferentHosts, expected 2 connections, got : %d", len(clientAddress))
+	}
+
+}
+
 func TestEngineModeDdosifyKeepAlive(t *testing.T) {
 	t.Parallel()
 
@@ -1888,16 +2027,14 @@ func TestEngineModeDdosifyKeepAlive(t *testing.T) {
 	h.IterationCount = 2
 	h.Scenario.Steps = make([]types.ScenarioStep, 2)
 	h.Scenario.Steps[0] = types.ScenarioStep{
-		ID:      1,
-		Method:  "GET",
-		URL:     host.URL + pathFirst,
-		Headers: map[string]string{"ID": "1"},
+		ID:     1,
+		Method: "GET",
+		URL:    host.URL + pathFirst,
 	}
 	h.Scenario.Steps[1] = types.ScenarioStep{
-		ID:      2,
-		Method:  "GET",
-		URL:     host.URL + pathSecond,
-		Headers: map[string]string{"ID": "2"},
+		ID:     2,
+		Method: "GET",
+		URL:    host.URL + pathSecond,
 	}
 
 	// Act

From 5be3c0ce0c1d0fce6edd73b14cc0f168c4dc8ad6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Wed, 22 Feb 2023 11:21:31 +0000
Subject: [PATCH 30/32] add engine mode to config json

---
 config_examples/config.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/config_examples/config.json b/config_examples/config.json
index a642db5b..6df22987 100644
--- a/config_examples/config.json
+++ b/config_examples/config.json
@@ -4,6 +4,7 @@
     "iteration_count": 30,
     "debug" : false, // use this field for debugging, see verbose result
     "load_type": "linear",
+    "engine_mode": "distinct-user", // could be one of  "distinct-user","repeated-user", or default mode "ddosify"
     "duration": 5,
     "manual_load": [
         {"duration": 5, "count": 5},

From 18ae153745d95dc555d9254436a6a24cf6c1bdef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Wed, 22 Feb 2023 12:29:59 +0000
Subject: [PATCH 31/32] add engine mode to readme

---
 README.md | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/README.md b/README.md
index f7f24890..2ddcc7d1 100644
--- a/README.md
+++ b/README.md
@@ -274,6 +274,12 @@ There is an example config file at [config_examples/config.json](/config_example
 - `output` *optional*
 
     This is the equivalent of the `-o` flag.
+- `engine_mode` *optional*
+    Can be one of `distinct-user`, `repeated-user`, or default mode `ddosify`. 
+    - `distinct-user` mode simulates a new user for every iteration.
+    - `repeated-user` mode can use pre-used user in subsequent iterations.
+    - `ddosify` mode is default mode of the engine. In this mode engine runs in its max capacity, and does not show user simulation behaviour.
+
 - `env` *optional*
     Scenario-scoped global variables. Note that dynamic variables changes every iteration. 
     ```json
@@ -282,6 +288,7 @@ There is an example config file at [config_examples/config.json](/config_example
             "randomCountry" : "{{_randomCountry}}"
     }
     ``` 
+
 - `data` *optional*
     Config for loading test data from a CSV file.
     [CSV data](https://github.com/ddosify/ddosify/tree/master/config/config_testdata/test.csv) used in below config. 

From fd3d1fdfce3bf8e1f00b5d3557e0aad9d55c41b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kenan=20Faruk=20=C3=87ak=C4=B1r?=
 <kenanfarukcakir@gmail.com>
Date: Fri, 24 Feb 2023 12:15:57 +0000
Subject: [PATCH 32/32] remove keep-alive from others, look for Connection
 header instead

---
 README.md                                            |  3 +--
 .../benchmark/config_correlation_load_1.json         |  3 ---
 .../benchmark/config_correlation_load_2.json         |  3 ---
 .../benchmark/config_correlation_load_3.json         |  3 ---
 .../benchmark/config_correlation_load_4.json         |  3 ---
 .../benchmark/config_correlation_load_5.json         |  3 ---
 config/config_testdata/config.json                   |  1 -
 config/config_testdata/config_data_csv.json          |  1 -
 config/config_testdata/config_debug_false.json       |  1 -
 config/config_testdata/config_debug_mode.json        |  1 -
 config/config_testdata/config_env_vars.json          |  1 -
 config/config_testdata/config_incorrect.json         |  2 --
 config/config_testdata/config_iteration_count.json   |  1 -
 .../config_iteration_count_over_req_count.json       |  1 -
 config/json_test.go                                  | 12 +++---------
 config_examples/config.json                          |  1 -
 core/engine_test.go                                  | 10 +++++-----
 core/scenario/requester/http.go                      | 12 ++++++------
 core/scenario/requester/http_test.go                 | 11 +++++------
 19 files changed, 20 insertions(+), 53 deletions(-)

diff --git a/README.md b/README.md
index 2ddcc7d1..6e20aafb 100644
--- a/README.md
+++ b/README.md
@@ -232,7 +232,7 @@ The features you can use by config file;
 - Custom load type creation
 - Payload from a file
 - Multipart/form-data payload
-- Extra connection configuration, like *keep-alive* enable/disable logic
+- Extra connection configuration
 - HTTP2 support
 
 
@@ -501,7 +501,6 @@ There is an example config file at [config_examples/config.json](/config_example
 
         ```json
         "others": {
-            "keep-alive": true,              // Default true
             "disable-compression": false,    // Default true
             "h2": true,                      // Enables HTTP/2. Default false.
             "disable-redirect": true         // Default false
diff --git a/config/config_testdata/benchmark/config_correlation_load_1.json b/config/config_testdata/benchmark/config_correlation_load_1.json
index 16984586..9a969a0b 100644
--- a/config/config_testdata/benchmark/config_correlation_load_1.json
+++ b/config/config_testdata/benchmark/config_correlation_load_1.json
@@ -11,7 +11,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -37,7 +36,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -56,7 +54,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
diff --git a/config/config_testdata/benchmark/config_correlation_load_2.json b/config/config_testdata/benchmark/config_correlation_load_2.json
index 15b4c8b2..f62bc132 100644
--- a/config/config_testdata/benchmark/config_correlation_load_2.json
+++ b/config/config_testdata/benchmark/config_correlation_load_2.json
@@ -11,7 +11,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -37,7 +36,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -56,7 +54,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
diff --git a/config/config_testdata/benchmark/config_correlation_load_3.json b/config/config_testdata/benchmark/config_correlation_load_3.json
index 0e9343ec..f4d78694 100644
--- a/config/config_testdata/benchmark/config_correlation_load_3.json
+++ b/config/config_testdata/benchmark/config_correlation_load_3.json
@@ -11,7 +11,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -37,7 +36,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -56,7 +54,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
diff --git a/config/config_testdata/benchmark/config_correlation_load_4.json b/config/config_testdata/benchmark/config_correlation_load_4.json
index f386f549..dd2908c7 100644
--- a/config/config_testdata/benchmark/config_correlation_load_4.json
+++ b/config/config_testdata/benchmark/config_correlation_load_4.json
@@ -12,7 +12,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -38,7 +37,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -57,7 +55,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
diff --git a/config/config_testdata/benchmark/config_correlation_load_5.json b/config/config_testdata/benchmark/config_correlation_load_5.json
index d3179055..f051bab8 100644
--- a/config/config_testdata/benchmark/config_correlation_load_5.json
+++ b/config/config_testdata/benchmark/config_correlation_load_5.json
@@ -12,7 +12,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -38,7 +37,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
@@ -57,7 +55,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
diff --git a/config/config_testdata/config.json b/config/config_testdata/config.json
index e223fb95..6ace2b82 100644
--- a/config/config_testdata/config.json
+++ b/config/config_testdata/config.json
@@ -12,7 +12,6 @@
             "timeout": 3,
             "sleep": "1000",
             "others": {
-                "keep-alive": true
             }
         },
         {
diff --git a/config/config_testdata/config_data_csv.json b/config/config_testdata/config_data_csv.json
index 13b6881d..24d5bbf8 100644
--- a/config/config_testdata/config_data_csv.json
+++ b/config/config_testdata/config_data_csv.json
@@ -10,7 +10,6 @@
               "method": "GET",
               "others": {
                 "h2": false,
-                "keep-alive": true,
                 "disable-redirect": true,
                 "disable-compression": false
               },
diff --git a/config/config_testdata/config_debug_false.json b/config/config_testdata/config_debug_false.json
index 92e18baa..874d8d7a 100644
--- a/config/config_testdata/config_debug_false.json
+++ b/config/config_testdata/config_debug_false.json
@@ -13,7 +13,6 @@
             "timeout": 3,
             "sleep": "1000",
             "others": {
-                "keep-alive": true
             }
         },
         {
diff --git a/config/config_testdata/config_debug_mode.json b/config/config_testdata/config_debug_mode.json
index 1e661c64..08ed4adc 100644
--- a/config/config_testdata/config_debug_mode.json
+++ b/config/config_testdata/config_debug_mode.json
@@ -13,7 +13,6 @@
             "timeout": 3,
             "sleep": "1000",
             "others": {
-                "keep-alive": true
             }
         },
         {
diff --git a/config/config_testdata/config_env_vars.json b/config/config_testdata/config_env_vars.json
index 93c5a7ea..6b670b6b 100644
--- a/config/config_testdata/config_env_vars.json
+++ b/config/config_testdata/config_env_vars.json
@@ -12,7 +12,6 @@
             "timeout": 3,
             "sleep": "1000",
             "others": {
-                "keep-alive": true
             },
             "capture_env": {
                 "ENV_VAR1" :{"json_path":""},
diff --git a/config/config_testdata/config_incorrect.json b/config/config_testdata/config_incorrect.json
index f31b65d8..c1d17c24 100644
--- a/config/config_testdata/config_incorrect.json
+++ b/config/config_testdata/config_incorrect.json
@@ -19,7 +19,6 @@
             "payload": "body yt kanl adnlandlandaln",
             "timeout": 1,
             "others": {
-                "keep-alive": true
             }
         },
         {
@@ -33,7 +32,6 @@
             "payload_file": "config_examples/payload.txt",
             "timeout": 1,
             "others": {
-                "keep-alive": false
             }
         },
     ],
diff --git a/config/config_testdata/config_iteration_count.json b/config/config_testdata/config_iteration_count.json
index 54dc3612..e33a75a3 100644
--- a/config/config_testdata/config_iteration_count.json
+++ b/config/config_testdata/config_iteration_count.json
@@ -13,7 +13,6 @@
             "timeout": 3,
             "sleep": "1000",
             "others": {
-                "keep-alive": true
             }
         },
         {
diff --git a/config/config_testdata/config_iteration_count_over_req_count.json b/config/config_testdata/config_iteration_count_over_req_count.json
index bb6470f5..6e71eea8 100644
--- a/config/config_testdata/config_iteration_count_over_req_count.json
+++ b/config/config_testdata/config_iteration_count_over_req_count.json
@@ -13,7 +13,6 @@
             "timeout": 3,
             "sleep": "1000",
             "others": {
-                "keep-alive": true
             }
         },
         {
diff --git a/config/json_test.go b/config/json_test.go
index db4ef975..30718b59 100644
--- a/config/json_test.go
+++ b/config/json_test.go
@@ -90,9 +90,7 @@ func TestCreateHammer(t *testing.T) {
 					Timeout: 3,
 					Sleep:   "1000",
 					Payload: "payload str",
-					Custom: map[string]interface{}{
-						"keep-alive": true,
-					},
+					Custom:  map[string]interface{}{},
 				},
 				{
 					ID:      2,
@@ -147,9 +145,7 @@ func TestCreateHammerWithIterationCountInsteadOfReqCount(t *testing.T) {
 					Timeout: 3,
 					Sleep:   "1000",
 					Payload: "payload str",
-					Custom: map[string]interface{}{
-						"keep-alive": true,
-					},
+					Custom:  map[string]interface{}{},
 				},
 				{
 					ID:      2,
@@ -206,9 +202,7 @@ func TestCreateHammerWithIterationCountOverridesReqCount(t *testing.T) {
 					Timeout: 3,
 					Sleep:   "1000",
 					Payload: "payload str",
-					Custom: map[string]interface{}{
-						"keep-alive": true,
-					},
+					Custom:  map[string]interface{}{},
 				},
 				{
 					ID:   2,
diff --git a/config_examples/config.json b/config_examples/config.json
index 6df22987..01eafeb5 100644
--- a/config_examples/config.json
+++ b/config_examples/config.json
@@ -55,7 +55,6 @@
                 "password": "12345"
             },
             "others": {
-                "keep-alive": true,
                 "disable-compression": false,
                 "h2": true,
                 "disable-redirect": true
diff --git a/core/engine_test.go b/core/engine_test.go
index 2695465b..9830f7db 100644
--- a/core/engine_test.go
+++ b/core/engine_test.go
@@ -1946,10 +1946,10 @@ func TestEngineModeUserKeepAlive_StepsKeepAliveFalse(t *testing.T) {
 	h.Scenario.Steps = make([]types.ScenarioStep, 4)
 	// connection opened by 1 will not be reused
 	h.Scenario.Steps[0] = types.ScenarioStep{
-		ID:     1,
-		Method: "GET",
-		URL:    host1.URL + pathFirst,
-		Custom: map[string]interface{}{"keep-alive": false},
+		ID:      1,
+		Method:  "GET",
+		URL:     host1.URL + pathFirst,
+		Headers: map[string]string{"Connection": "close"},
 	}
 	// below will use the connection opened by 2
 	h.Scenario.Steps[1] = types.ScenarioStep{
@@ -1982,7 +1982,7 @@ func TestEngineModeUserKeepAlive_StepsKeepAliveFalse(t *testing.T) {
 
 	e.Start()
 
-	// one iteration, one host, 4 steps, one's keep-alive is false
+	// one iteration, one host, 4 steps, one's keep-alive is false (Connection: close)
 	if len(clientAddress) != 2 {
 		t.Errorf("TestEngineModeUserKeepAliveDifferentHosts, expected 2 connections, got : %d", len(clientAddress))
 	}
diff --git a/core/scenario/requester/http.go b/core/scenario/requester/http.go
index ca5d59bb..5ed359a9 100644
--- a/core/scenario/requester/http.go
+++ b/core/scenario/requester/http.go
@@ -485,8 +485,8 @@ func (h *HttpRequester) initTransport() *http.Transport {
 	}
 
 	tr.DisableKeepAlives = false
-	if val, ok := h.packet.Custom["keep-alive"]; ok {
-		tr.DisableKeepAlives = !val.(bool)
+	if h.packet.Headers["Connection"] == "close" {
+		tr.DisableKeepAlives = true
 	}
 	if val, ok := h.packet.Custom["disable-compression"]; ok {
 		tr.DisableCompression = val.(bool)
@@ -505,8 +505,8 @@ func (h *HttpRequester) updateTransport(tr *http.Transport) {
 	tr.Proxy = http.ProxyURL(h.proxyAddr)
 
 	tr.DisableKeepAlives = false
-	if val, ok := h.packet.Custom["keep-alive"]; ok {
-		tr.DisableKeepAlives = !val.(bool)
+	if h.packet.Headers["Connection"] == "close" {
+		tr.DisableKeepAlives = true
 	}
 	if val, ok := h.packet.Custom["disable-compression"]; ok {
 		tr.DisableCompression = val.(bool)
@@ -567,8 +567,8 @@ func (h *HttpRequester) initRequestInstance() (err error) {
 
 	// If keep-alive is false, prevent the reuse of the previous TCP connection at the request layer also.
 	h.request.Close = false
-	if val, ok := h.packet.Custom["keep-alive"]; ok {
-		h.request.Close = !val.(bool)
+	if h.packet.Headers["Connection"] == "close" {
+		h.request.Close = true
 	}
 	return
 }
diff --git a/core/scenario/requester/http_test.go b/core/scenario/requester/http_test.go
index d1ee92a7..b661d6bc 100644
--- a/core/scenario/requester/http_test.go
+++ b/core/scenario/requester/http_test.go
@@ -90,9 +90,9 @@ func TestInitClient(t *testing.T) {
 		Method:  http.MethodGet,
 		URL:     "https://test.com",
 		Timeout: types.DefaultTimeout,
+		Headers: map[string]string{"Connection": "close"},
 		Custom: map[string]interface{}{
 			"disable-redirect":    true,
-			"keep-alive":          false,
 			"disable-compression": true,
 			"hostname":            "dummy.com",
 		},
@@ -279,11 +279,9 @@ func TestInitRequest(t *testing.T) {
 			Password: "123",
 		},
 		Headers: map[string]string{
-			"Header1": "Value1",
-			"Header2": "Value2",
-		},
-		Custom: map[string]interface{}{
-			"keep-alive": false,
+			"Header1":    "Value1",
+			"Header2":    "Value2",
+			"Connection": "close",
 		},
 	}
 	expectedWithoutKeepAlive, _ := http.NewRequest(sWithoutKeepAlive.Method,
@@ -292,6 +290,7 @@ func TestInitRequest(t *testing.T) {
 	expectedWithoutKeepAlive.Header = make(http.Header)
 	expectedWithoutKeepAlive.Header.Set("Header1", "Value1")
 	expectedWithoutKeepAlive.Header.Set("Header2", "Value2")
+	expectedWithoutKeepAlive.Header.Set("Connection", "close")
 	expectedWithoutKeepAlive.SetBasicAuth(sWithoutKeepAlive.Auth.Username, sWithoutKeepAlive.Auth.Password)
 
 	// Sub Tests