diff --git a/pkg/utils/apiutil/apiutil.go b/pkg/utils/apiutil/apiutil.go
index bcab7c8e9e7..0b72b9af10f 100644
--- a/pkg/utils/apiutil/apiutil.go
+++ b/pkg/utils/apiutil/apiutil.go
@@ -57,6 +57,8 @@ const (
 	XForwardedPortHeader = "X-Forwarded-Port"
 	// XRealIPHeader is used to mark the real client IP.
 	XRealIPHeader = "X-Real-Ip"
+	// ForwardToMicroServiceHeader is used to mark the request is forwarded to micro service.
+	ForwardToMicroServiceHeader = "Forward-To-Micro-Service"
 
 	// ErrRedirectFailed is the error message for redirect failed.
 	ErrRedirectFailed = "redirect failed"
diff --git a/pkg/utils/apiutil/serverapi/middleware.go b/pkg/utils/apiutil/serverapi/middleware.go
index 6682f4aabbc..1b97ce4d6aa 100644
--- a/pkg/utils/apiutil/serverapi/middleware.go
+++ b/pkg/utils/apiutil/serverapi/middleware.go
@@ -171,6 +171,7 @@ func (h *redirector) ServeHTTP(w http.ResponseWriter, r *http.Request, next http
 			return
 		}
 		clientUrls = append(clientUrls, targetAddr)
+		w.Header().Set(apiutil.ForwardToMicroServiceHeader, "true")
 	} else {
 		leader := h.s.GetMember().GetLeader()
 		if leader == nil {
diff --git a/pkg/utils/testutil/api_check.go b/pkg/utils/testutil/api_check.go
index fcc445b7e7a..d11d575967d 100644
--- a/pkg/utils/testutil/api_check.go
+++ b/pkg/utils/testutil/api_check.go
@@ -23,56 +23,71 @@ import (
 	"github.com/tikv/pd/pkg/utils/apiutil"
 )
 
-// Status is used to check whether http response code is equal given code
-func Status(re *require.Assertions, code int) func([]byte, int) {
-	return func(resp []byte, i int) {
+// Status is used to check whether http response code is equal given code.
+func Status(re *require.Assertions, code int) func([]byte, int, http.Header) {
+	return func(resp []byte, i int, _ http.Header) {
 		re.Equal(code, i, "resp: "+string(resp))
 	}
 }
 
-// StatusOK is used to check whether http response code is equal http.StatusOK
-func StatusOK(re *require.Assertions) func([]byte, int) {
+// StatusOK is used to check whether http response code is equal http.StatusOK.
+func StatusOK(re *require.Assertions) func([]byte, int, http.Header) {
 	return Status(re, http.StatusOK)
 }
 
-// StatusNotOK is used to check whether http response code is not equal http.StatusOK
-func StatusNotOK(re *require.Assertions) func([]byte, int) {
-	return func(_ []byte, i int) {
+// StatusNotOK is used to check whether http response code is not equal http.StatusOK.
+func StatusNotOK(re *require.Assertions) func([]byte, int, http.Header) {
+	return func(_ []byte, i int, _ http.Header) {
 		re.NotEqual(http.StatusOK, i)
 	}
 }
 
-// ExtractJSON is used to check whether given data can be extracted successfully
-func ExtractJSON(re *require.Assertions, data interface{}) func([]byte, int) {
-	return func(res []byte, _ int) {
+// ExtractJSON is used to check whether given data can be extracted successfully.
+func ExtractJSON(re *require.Assertions, data interface{}) func([]byte, int, http.Header) {
+	return func(res []byte, _ int, _ http.Header) {
 		re.NoError(json.Unmarshal(res, data))
 	}
 }
 
-// StringContain is used to check whether response context contains given string
-func StringContain(re *require.Assertions, sub string) func([]byte, int) {
-	return func(res []byte, _ int) {
+// StringContain is used to check whether response context contains given string.
+func StringContain(re *require.Assertions, sub string) func([]byte, int, http.Header) {
+	return func(res []byte, _ int, _ http.Header) {
 		re.Contains(string(res), sub)
 	}
 }
 
-// StringEqual is used to check whether response context equal given string
-func StringEqual(re *require.Assertions, str string) func([]byte, int) {
-	return func(res []byte, _ int) {
+// StringEqual is used to check whether response context equal given string.
+func StringEqual(re *require.Assertions, str string) func([]byte, int, http.Header) {
+	return func(res []byte, _ int, _ http.Header) {
 		re.Contains(string(res), str)
 	}
 }
 
-// ReadGetJSON is used to do get request and check whether given data can be extracted successfully
-func ReadGetJSON(re *require.Assertions, client *http.Client, url string, data interface{}) error {
+// WithHeader is used to check whether response header contains given key and value.
+func WithHeader(re *require.Assertions, key, value string) func([]byte, int, http.Header) {
+	return func(_ []byte, _ int, header http.Header) {
+		re.Equal(value, header.Get(key))
+	}
+}
+
+// WithoutHeader is used to check whether response header does not contain given key.
+func WithoutHeader(re *require.Assertions, key string) func([]byte, int, http.Header) {
+	return func(_ []byte, _ int, header http.Header) {
+		re.Empty(header.Get(key))
+	}
+}
+
+// ReadGetJSON is used to do get request and check whether given data can be extracted successfully.
+func ReadGetJSON(re *require.Assertions, client *http.Client, url string, data interface{}, checkOpts ...func([]byte, int, http.Header)) error {
 	resp, err := apiutil.GetJSON(client, url, nil)
 	if err != nil {
 		return err
 	}
-	return checkResp(resp, StatusOK(re), ExtractJSON(re, data))
+	checkOpts = append(checkOpts, StatusOK(re), ExtractJSON(re, data))
+	return checkResp(resp, checkOpts...)
 }
 
-// ReadGetJSONWithBody is used to do get request with input and check whether given data can be extracted successfully
+// ReadGetJSONWithBody is used to do get request with input and check whether given data can be extracted successfully.
 func ReadGetJSONWithBody(re *require.Assertions, client *http.Client, url string, input []byte, data interface{}) error {
 	resp, err := apiutil.GetJSON(client, url, input)
 	if err != nil {
@@ -81,8 +96,8 @@ func ReadGetJSONWithBody(re *require.Assertions, client *http.Client, url string
 	return checkResp(resp, StatusOK(re), ExtractJSON(re, data))
 }
 
-// CheckPostJSON is used to do post request and do check options
-func CheckPostJSON(client *http.Client, url string, data []byte, checkOpts ...func([]byte, int)) error {
+// CheckPostJSON is used to do post request and do check options.
+func CheckPostJSON(client *http.Client, url string, data []byte, checkOpts ...func([]byte, int, http.Header)) error {
 	resp, err := apiutil.PostJSON(client, url, data)
 	if err != nil {
 		return err
@@ -90,8 +105,8 @@ func CheckPostJSON(client *http.Client, url string, data []byte, checkOpts ...fu
 	return checkResp(resp, checkOpts...)
 }
 
-// CheckGetJSON is used to do get request and do check options
-func CheckGetJSON(client *http.Client, url string, data []byte, checkOpts ...func([]byte, int)) error {
+// CheckGetJSON is used to do get request and do check options.
+func CheckGetJSON(client *http.Client, url string, data []byte, checkOpts ...func([]byte, int, http.Header)) error {
 	resp, err := apiutil.GetJSON(client, url, data)
 	if err != nil {
 		return err
@@ -99,8 +114,8 @@ func CheckGetJSON(client *http.Client, url string, data []byte, checkOpts ...fun
 	return checkResp(resp, checkOpts...)
 }
 
-// CheckPatchJSON is used to do patch request and do check options
-func CheckPatchJSON(client *http.Client, url string, data []byte, checkOpts ...func([]byte, int)) error {
+// CheckPatchJSON is used to do patch request and do check options.
+func CheckPatchJSON(client *http.Client, url string, data []byte, checkOpts ...func([]byte, int, http.Header)) error {
 	resp, err := apiutil.PatchJSON(client, url, data)
 	if err != nil {
 		return err
@@ -108,14 +123,14 @@ func CheckPatchJSON(client *http.Client, url string, data []byte, checkOpts ...f
 	return checkResp(resp, checkOpts...)
 }
 
-func checkResp(resp *http.Response, checkOpts ...func([]byte, int)) error {
+func checkResp(resp *http.Response, checkOpts ...func([]byte, int, http.Header)) error {
 	res, err := io.ReadAll(resp.Body)
 	resp.Body.Close()
 	if err != nil {
 		return err
 	}
 	for _, opt := range checkOpts {
-		opt(res, resp.StatusCode)
+		opt(res, resp.StatusCode, resp.Header)
 	}
 	return nil
 }
diff --git a/server/api/hot_status_test.go b/server/api/hot_status_test.go
index a1d1bbc2617..d3d495f86fa 100644
--- a/server/api/hot_status_test.go
+++ b/server/api/hot_status_test.go
@@ -17,6 +17,7 @@ package api
 import (
 	"encoding/json"
 	"fmt"
+	"net/http"
 	"testing"
 	"time"
 
@@ -92,7 +93,7 @@ func (suite *hotStatusTestSuite) TestGetHistoryHotRegionsTimeRange() {
 		StartTime: now.UnixNano() / int64(time.Millisecond),
 		EndTime:   now.Add(10*time.Second).UnixNano() / int64(time.Millisecond),
 	}
-	check := func(res []byte, statusCode int) {
+	check := func(res []byte, statusCode int, _ http.Header) {
 		suite.Equal(200, statusCode)
 		historyHotRegions := &storage.HistoryHotRegions{}
 		json.Unmarshal(res, historyHotRegions)
@@ -177,7 +178,7 @@ func (suite *hotStatusTestSuite) TestGetHistoryHotRegionsIDAndTypes() {
 		IsLearners:     []bool{false},
 		EndTime:        now.Add(10*time.Minute).UnixNano() / int64(time.Millisecond),
 	}
-	check := func(res []byte, statusCode int) {
+	check := func(res []byte, statusCode int, _ http.Header) {
 		suite.Equal(200, statusCode)
 		historyHotRegions := &storage.HistoryHotRegions{}
 		json.Unmarshal(res, historyHotRegions)
diff --git a/server/api/region_test.go b/server/api/region_test.go
index 63da19ab082..acd305884d4 100644
--- a/server/api/region_test.go
+++ b/server/api/region_test.go
@@ -408,7 +408,7 @@ func (suite *regionTestSuite) TestSplitRegions() {
 		hex.EncodeToString([]byte("bbb")),
 		hex.EncodeToString([]byte("ccc")),
 		hex.EncodeToString([]byte("ddd")))
-	checkOpt := func(res []byte, code int) {
+	checkOpt := func(res []byte, code int, _ http.Header) {
 		s := &struct {
 			ProcessedPercentage int      `json:"processed-percentage"`
 			NewRegionsID        []uint64 `json:"regions-id"`
diff --git a/server/api/rule_test.go b/server/api/rule_test.go
index d2000eb9562..4cea1523401 100644
--- a/server/api/rule_test.go
+++ b/server/api/rule_test.go
@@ -829,7 +829,7 @@ func (suite *ruleTestSuite) TestBundleBadRequest() {
 	}
 	for _, testCase := range testCases {
 		err := tu.CheckPostJSON(testDialClient, suite.urlPrefix+testCase.uri, []byte(testCase.data),
-			func(_ []byte, code int) {
+			func(_ []byte, code int, _ http.Header) {
 				suite.Equal(testCase.ok, code == http.StatusOK)
 			})
 		suite.NoError(err)
diff --git a/tests/integrations/mcs/scheduling/api_test.go b/tests/integrations/mcs/scheduling/api_test.go
index 03db3433ec9..ea9cd2df9c5 100644
--- a/tests/integrations/mcs/scheduling/api_test.go
+++ b/tests/integrations/mcs/scheduling/api_test.go
@@ -2,6 +2,7 @@ package scheduling_test
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"testing"
@@ -9,6 +10,7 @@ import (
 
 	"github.com/stretchr/testify/suite"
 	_ "github.com/tikv/pd/pkg/mcs/scheduling/server/apis/v1"
+	"github.com/tikv/pd/pkg/utils/apiutil"
 	"github.com/tikv/pd/pkg/utils/tempurl"
 	"github.com/tikv/pd/pkg/utils/testutil"
 	"github.com/tikv/pd/tests"
@@ -119,21 +121,40 @@ func (suite *apiTestSuite) TestAPIForward() {
 	var resp map[string]interface{}
 
 	// Test opeartor
-	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "operators"), &slice)
+	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "operators"), &slice,
+		testutil.WithHeader(re, apiutil.ForwardToMicroServiceHeader, "true"))
 	re.NoError(err)
 	re.Len(slice, 0)
 
-	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "operators/2"), &resp)
+	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "operators/2"), &resp,
+		testutil.WithHeader(re, apiutil.ForwardToMicroServiceHeader, "true"))
 	re.NoError(err)
 	re.Nil(resp)
 
-	// Test checker
-	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "checker/merge"), &resp)
+	// Test checker: only read-only requests are forwarded
+	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "checker/merge"), &resp,
+		testutil.WithHeader(re, apiutil.ForwardToMicroServiceHeader, "true"))
 	re.NoError(err)
 	suite.False(resp["paused"].(bool))
 
-	// Test scheduler
-	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "schedulers"), &slice)
+	input := make(map[string]interface{})
+	input["delay"] = 10
+	pauseArgs, err := json.Marshal(input)
+	suite.NoError(err)
+	err = testutil.CheckPostJSON(testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "checker/merge"), pauseArgs,
+		testutil.StatusOK(re), testutil.WithoutHeader(re, apiutil.PDRedirectorHeader))
+	suite.NoError(err)
+
+	// Test scheduler: only read-only requests are forwarded
+	err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "schedulers"), &slice,
+		testutil.WithHeader(re, apiutil.ForwardToMicroServiceHeader, "true"))
 	re.NoError(err)
 	re.Contains(slice, "balance-leader-scheduler")
+
+	input["delay"] = 30
+	pauseArgs, err = json.Marshal(input)
+	suite.NoError(err)
+	err = testutil.CheckPostJSON(testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "schedulers/all"), pauseArgs,
+		testutil.StatusOK(re), testutil.WithoutHeader(re, apiutil.ForwardToMicroServiceHeader))
+	suite.NoError(err)
 }