diff --git a/src/api/rest/server/common/config.go b/src/api/rest/server/common/config.go
index b34bebb67..9cd588b72 100644
--- a/src/api/rest/server/common/config.go
+++ b/src/api/rest/server/common/config.go
@@ -28,6 +28,7 @@ import (
 	"github.com/rs/zerolog/log"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 )
 
@@ -47,17 +48,17 @@ func RestInitConfig(c echo.Context) error {
 
 	if err := Validate(c, []string{"configId"}); err != nil {
 		log.Error().Err(err).Msg("")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	err := common.InitConfig(c.Param("configId"))
 	if err != nil {
 		err := fmt.Errorf("Failed to init the config " + c.Param("configId"))
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	} else {
 		// return SendMessage(c, http.StatusOK, "The config "+c.Param("configId")+" has been initialized.")
 		content := map[string]string{"message": "The config " + c.Param("configId") + " has been initialized."}
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	}
 }
 
@@ -83,9 +84,9 @@ func RestGetConfig(c echo.Context) error {
 	content, err := common.GetConfig(c.Param("configId"))
 	if err != nil {
 		err := fmt.Errorf("Failed to find the config " + c.Param("configId"))
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	} else {
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	}
 }
 
@@ -112,7 +113,7 @@ func RestGetAllConfig(c echo.Context) error {
 
 	configList, err := common.ListConfig()
 	content.Config = configList
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPostConfig godoc
@@ -131,12 +132,12 @@ func RestPostConfig(c echo.Context) error {
 
 	u := &model.ConfigReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	log.Debug().Msg("[Creating or Updating Config]")
 	content, err := common.UpdateConfig(u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -155,7 +156,7 @@ func RestInitAllConfig(c echo.Context) error {
 	err := common.InitAllConfig()
 	content := map[string]string{
 		"message": "All configs has been initialized"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetRequest godoc
@@ -173,7 +174,7 @@ func RestInitAllConfig(c echo.Context) error {
 func RestGetRequest(c echo.Context) error {
 	reqId := c.Param("reqId")
 
-	if details, ok := common.RequestMap.Load(reqId); ok {
+	if details, ok := clientManager.RequestMap.Load(reqId); ok {
 		return Send(c, http.StatusOK, details)
 	}
 
@@ -206,11 +207,11 @@ func RestGetAllRequests(c echo.Context) error {
 		timeLimit = time.Now().Add(-time.Duration(minutes) * time.Minute)
 	}
 
-	var allRequests []common.RequestDetails
+	var allRequests []clientManager.RequestDetails
 
 	// Filtering the requests
-	common.RequestMap.Range(func(key, value interface{}) bool {
-		if details, ok := value.(common.RequestDetails); ok {
+	clientManager.RequestMap.Range(func(key, value interface{}) bool {
+		if details, ok := value.(clientManager.RequestDetails); ok {
 			if (statusFilter == "" || strings.ToLower(details.Status) == statusFilter) &&
 				(methodFilter == "" || strings.ToLower(details.RequestInfo.Method) == methodFilter) &&
 				(urlFilter == "" || strings.Contains(strings.ToLower(details.RequestInfo.URL), urlFilter)) &&
@@ -239,7 +240,7 @@ func RestGetAllRequests(c echo.Context) error {
 		}
 	}
 
-	return Send(c, http.StatusOK, map[string][]common.RequestDetails{"requests": allRequests})
+	return Send(c, http.StatusOK, map[string][]clientManager.RequestDetails{"requests": allRequests})
 }
 
 // RestDeleteRequest godoc
@@ -255,8 +256,8 @@ func RestGetAllRequests(c echo.Context) error {
 func RestDeleteRequest(c echo.Context) error {
 	reqId := c.Param("reqId")
 
-	if _, ok := common.RequestMap.Load(reqId); ok {
-		common.RequestMap.Delete(reqId)
+	if _, ok := clientManager.RequestMap.Load(reqId); ok {
+		clientManager.RequestMap.Delete(reqId)
 		return SendMessage(c, http.StatusOK, "Request deleted successfully")
 	}
 
@@ -273,8 +274,8 @@ func RestDeleteRequest(c echo.Context) error {
 // @Success 200 {object} model.SimpleMsg
 // @Router /requests [delete]
 func RestDeleteAllRequests(c echo.Context) error {
-	common.RequestMap.Range(func(key, value interface{}) bool {
-		common.RequestMap.Delete(key)
+	clientManager.RequestMap.Range(func(key, value interface{}) bool {
+		clientManager.RequestMap.Delete(key)
 		return true
 	})
 
diff --git a/src/api/rest/server/common/label/label.go b/src/api/rest/server/common/label/label.go
index e8fc704c8..6db7b9039 100644
--- a/src/api/rest/server/common/label/label.go
+++ b/src/api/rest/server/common/label/label.go
@@ -19,7 +19,7 @@ import (
 
 	"github.com/labstack/echo/v4"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 )
@@ -46,7 +46,7 @@ func RestCreateOrUpdateLabel(c echo.Context) error {
 	// Parse the incoming request body to get the labels
 	var labelReq model.Label
 	if err := c.Bind(&labelReq); err != nil {
-		return common.EndRequestWithLog(c, fmt.Errorf("Invalid request body"), nil)
+		return clientManager.EndRequestWithLog(c, fmt.Errorf("Invalid request body"), nil)
 	}
 
 	// Get the resource key
@@ -55,10 +55,10 @@ func RestCreateOrUpdateLabel(c echo.Context) error {
 	// Create or update the label in the KV store
 	err := label.CreateOrUpdateLabel(labelType, uid, resourceKey, labelReq.Labels)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
-	return common.EndRequestWithLog(c, nil, map[string]string{"message": "Label created or updated successfully"})
+	return clientManager.EndRequestWithLog(c, nil, map[string]string{"message": "Label created or updated successfully"})
 }
 
 // RestRemoveLabel godoc
@@ -84,10 +84,10 @@ func RestRemoveLabel(c echo.Context) error {
 	// Remove the label from the KV store
 	err := label.RemoveLabel(labelType, uid, key)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
-	return common.EndRequestWithLog(c, nil, map[string]string{"message": "Label removed successfully"})
+	return clientManager.EndRequestWithLog(c, nil, map[string]string{"message": "Label removed successfully"})
 }
 
 // RestGetLabels godoc
@@ -111,10 +111,10 @@ func RestGetLabels(c echo.Context) error {
 	// Get the labels from the KV store
 	labelInfo, err := label.GetLabels(labelType, uid)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
-	return common.EndRequestWithLog(c, nil, labelInfo)
+	return clientManager.EndRequestWithLog(c, nil, labelInfo)
 }
 
 // ResourcesResponse is a struct to wrap the results of a label selector query
@@ -149,7 +149,7 @@ func RestGetResourcesByLabelSelector(c echo.Context) error {
 	// Get resources based on the label selector
 	resources, err := label.GetResourcesByLabelSelector(labelType, labelSelector)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// Wrap the results in a JSON object
@@ -157,7 +157,7 @@ func RestGetResourcesByLabelSelector(c echo.Context) error {
 		Results: resources,
 	}
 
-	return common.EndRequestWithLog(c, nil, response)
+	return clientManager.EndRequestWithLog(c, nil, response)
 }
 
 // RestGetSystemLabelInfo godoc
@@ -182,5 +182,5 @@ func RestGetSystemLabelInfo(c echo.Context) error {
 		LabelTypes:   labelTypes,
 	}
 
-	return common.EndRequestWithLog(c, nil, systemLabelInfo)
+	return clientManager.EndRequestWithLog(c, nil, systemLabelInfo)
 }
diff --git a/src/api/rest/server/common/namespace.go b/src/api/rest/server/common/namespace.go
index 8d392bdff..6f9030d10 100644
--- a/src/api/rest/server/common/namespace.go
+++ b/src/api/rest/server/common/namespace.go
@@ -18,22 +18,23 @@ import (
 	"github.com/labstack/echo/v4"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 )
 
 func RestCheckNs(c echo.Context) error {
 
 	if err := Validate(c, []string{"nsId"}); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	nsId := c.Param("nsId")
 	err := common.CheckString(nsId)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	content, err := common.CheckNs(nsId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestDelAllNs godoc
@@ -50,7 +51,7 @@ func RestDelAllNs(c echo.Context) error {
 
 	err := common.DelAllNs()
 	content := map[string]string{"message": "All namespaces has been deleted"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestDelNs godoc
@@ -67,12 +68,12 @@ func RestDelAllNs(c echo.Context) error {
 func RestDelNs(c echo.Context) error {
 
 	if err := Validate(c, []string{"nsId"}); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	err := common.DelNs(c.Param("nsId"))
 	content := map[string]string{"message": "The ns " + c.Param("nsId") + " has been deleted"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // JSONResult's data field will be overridden by the specific type
@@ -109,11 +110,11 @@ func RestGetAllNs(c echo.Context) error {
 		content := model.IdList{}
 		var err error
 		content.IdList, err = common.ListNsId()
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else {
 		nsList, err := common.ListNs()
 		content.Ns = nsList
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	}
 }
 
@@ -132,11 +133,11 @@ func RestGetAllNs(c echo.Context) error {
 func RestGetNs(c echo.Context) error {
 
 	if err := Validate(c, []string{"nsId"}); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := common.GetNs(c.Param("nsId"))
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPostNs godoc
@@ -155,11 +156,11 @@ func RestPostNs(c echo.Context) error {
 
 	u := &model.NsReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := common.CreateNs(u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -180,9 +181,9 @@ func RestPutNs(c echo.Context) error {
 
 	u := &model.NsReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := common.UpdateNs(c.Param("nsId"), u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/common/utility.go b/src/api/rest/server/common/utility.go
index fcc86d2e4..74d6e3a0e 100644
--- a/src/api/rest/server/common/utility.go
+++ b/src/api/rest/server/common/utility.go
@@ -26,6 +26,7 @@ import (
 	"github.com/labstack/echo/v4"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/rs/zerolog/log"
@@ -128,7 +129,7 @@ func RestCheckHTTPVersion(c echo.Context) error {
 func RestGetPublicKeyForCredentialEncryption(c echo.Context) error {
 
 	result, err := common.GetPublicKeyForCredentialEncryption()
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestRegisterCredential is a REST API handler for registering credentials.
@@ -147,11 +148,11 @@ func RestRegisterCredential(c echo.Context) error {
 
 	u := &model.CredentialReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := common.RegisterCredential(*u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -173,7 +174,7 @@ func RestGetConnConfig(c echo.Context) error {
 	connConfigName := c.Param("connConfigName")
 
 	content, err := common.GetConnConfig(connConfigName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -208,7 +209,7 @@ func RestGetConnConfigList(c echo.Context) error {
 	}
 
 	content, err := common.GetConnConfigList(filterCredentialHolder, filterVerifiedBool, filterRegionRepresentativeBool)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetProviderList func is a rest api wrapper for GetProviderList.
@@ -226,7 +227,7 @@ func RestGetConnConfigList(c echo.Context) error {
 func RestGetProviderList(c echo.Context) error {
 
 	content, err := common.GetProviderList()
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -250,7 +251,7 @@ func RestGetRegion(c echo.Context) error {
 	regionName := c.Param("regionName")
 
 	content, err := common.GetRegion(providerName, regionName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetRegions func is a rest api wrapper for GetRegion.
@@ -271,7 +272,7 @@ func RestGetRegions(c echo.Context) error {
 	providerName := c.Param("providerName")
 
 	content, err := common.GetRegions(providerName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetRegionListFromCsp func is a rest api wrapper for RetrieveRegionListFromCsp.
@@ -289,7 +290,7 @@ func RestGetRegions(c echo.Context) error {
 func RestGetRegionListFromCsp(c echo.Context) error {
 
 	content, err := common.RetrieveRegionListFromCsp()
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -308,7 +309,7 @@ func RestGetRegionListFromCsp(c echo.Context) error {
 func RestGetCloudInfo(c echo.Context) error {
 
 	content, err := common.GetCloudInfo()
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetK8sClusterInfo func is a rest api wrapper for K8sClsuterInfo.
@@ -326,7 +327,7 @@ func RestGetCloudInfo(c echo.Context) error {
 func RestGetK8sClusterInfo(c echo.Context) error {
 
 	content, err := common.GetK8sClusterInfo()
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // ObjectList struct consists of object IDs
@@ -476,7 +477,7 @@ func RestInspectResources(c echo.Context) error {
 	// 	content, err = infra.InspectVMs(u.ConnectionName)
 	// }
 	content, err = infra.InspectResources(u.ConnectionName, u.ResourceType)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -494,7 +495,7 @@ func RestInspectResources(c echo.Context) error {
 func RestInspectResourcesOverview(c echo.Context) error {
 
 	content, err := infra.InspectResourcesOverview()
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // Request struct for RestRegisterCspNativeResources
@@ -522,13 +523,13 @@ func RestRegisterCspNativeResources(c echo.Context) error {
 
 	u := &RestRegisterCspNativeResourcesRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	option := c.QueryParam("option")
 	mciFlag := c.QueryParam("mciFlag")
 
 	content, err := infra.RegisterCspNativeResources(u.NsId, u.ConnectionName, u.MciName, option, mciFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -556,13 +557,13 @@ func RestRegisterCspNativeResourcesAll(c echo.Context) error {
 
 	u := &RestRegisterCspNativeResourcesRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	option := c.QueryParam("option")
 	mciFlag := c.QueryParam("mciFlag")
 
 	content, err := infra.RegisterCspNativeResourcesAll(u.NsId, u.MciName, option, mciFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestForwardAnyReqToAny godoc
@@ -581,7 +582,7 @@ func RestForwardAnyReqToAny(c echo.Context) error {
 	reqPath := c.Param("*")
 	reqPath, err := url.PathUnescape(reqPath)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	log.Info().Msgf("reqPath: %s", reqPath)
@@ -591,13 +592,13 @@ func RestForwardAnyReqToAny(c echo.Context) error {
 	if c.Request().Body != nil {
 		bodyBytes, err := io.ReadAll(c.Request().Body)
 		if err != nil {
-			return common.EndRequestWithLog(c, fmt.Errorf("Failed to read request body: %v", err), nil)
+			return clientManager.EndRequestWithLog(c, fmt.Errorf("Failed to read request body: %v", err), nil)
 		}
 		requestBody = bodyBytes
 	} else {
-		requestBody = common.NoBody
+		requestBody = clientManager.NoBody
 	}
 
-	content, err := common.ForwardRequestToAny(reqPath, method, requestBody)
-	return common.EndRequestWithLog(c, err, content)
+	content, err := clientManager.ForwardRequestToAny(reqPath, method, requestBody)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/infra/benchmark.go b/src/api/rest/server/infra/benchmark.go
index 0281fc451..399f1a6b7 100644
--- a/src/api/rest/server/infra/benchmark.go
+++ b/src/api/rest/server/infra/benchmark.go
@@ -15,7 +15,7 @@ limitations under the License.
 package infra
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -49,7 +49,7 @@ func RestPostInstallBenchmarkAgentToMci(c echo.Context) error {
 
 	resultArray, err := infra.InstallBenchmarkAgentToMci(nsId, mciId, req, option)
 	if err != nil {
-		common.EndRequestWithLog(c, err, nil)
+		clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content := model.MciSshCmdResult{}
@@ -57,7 +57,7 @@ func RestPostInstallBenchmarkAgentToMci(c echo.Context) error {
 		content.Results = append(content.Results, v)
 	}
 
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -91,7 +91,7 @@ func RestGetAllBenchmark(c echo.Context) error {
 	}
 
 	content, err := infra.RunAllBenchmarks(nsId, mciId, req.Host)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetLatencyBenchmark godoc
@@ -113,7 +113,7 @@ func RestGetBenchmarkLatency(c echo.Context) error {
 	mciId := c.Param("mciId")
 
 	content, err := infra.RunLatencyBenchmark(nsId, mciId, "")
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 type RestGetBenchmarkRequest struct {
@@ -147,5 +147,5 @@ func RestGetBenchmark(c echo.Context) error {
 	}
 
 	content, err := infra.CoreGetBenchmark(nsId, mciId, action, req.Host)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/infra/control.go b/src/api/rest/server/infra/control.go
index 7a0068a14..671f66f12 100644
--- a/src/api/rest/server/infra/control.go
+++ b/src/api/rest/server/infra/control.go
@@ -17,7 +17,7 @@ package infra
 import (
 	"fmt"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -55,14 +55,14 @@ func RestGetControlMci(c echo.Context) error {
 
 		resultString, err := infra.HandleMciAction(nsId, mciId, action, forceOption)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, returnObj)
+			return clientManager.EndRequestWithLog(c, err, returnObj)
 		}
 		returnObj.Message = resultString
-		return common.EndRequestWithLog(c, err, returnObj)
+		return clientManager.EndRequestWithLog(c, err, returnObj)
 
 	} else {
 		err := fmt.Errorf("'action' should be one of these: suspend, resume, reboot, terminate, refine, continue, withdraw")
-		return common.EndRequestWithLog(c, err, returnObj)
+		return clientManager.EndRequestWithLog(c, err, returnObj)
 	}
 }
 
@@ -101,14 +101,14 @@ func RestGetControlMciVm(c echo.Context) error {
 
 		resultString, err := infra.HandleMciVmAction(nsId, mciId, vmId, action, forceOption)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, returnObj)
+			return clientManager.EndRequestWithLog(c, err, returnObj)
 		}
 		returnObj.Message = resultString
-		return common.EndRequestWithLog(c, err, returnObj)
+		return clientManager.EndRequestWithLog(c, err, returnObj)
 
 	} else {
 		err := fmt.Errorf("'action' should be one of these: suspend, resume, reboot, terminate, refine")
-		return common.EndRequestWithLog(c, err, returnObj)
+		return clientManager.EndRequestWithLog(c, err, returnObj)
 	}
 }
 
@@ -140,7 +140,7 @@ func RestPostMciVmSnapshot(c echo.Context) error {
 
 	result, err := infra.CreateVmSnapshot(nsId, mciId, vmId, u.Name)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, model.SimpleMsg{Message: "Failed to create a snapshot"})
+		return clientManager.EndRequestWithLog(c, err, model.SimpleMsg{Message: "Failed to create a snapshot"})
 	}
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
diff --git a/src/api/rest/server/infra/loadbalance.go b/src/api/rest/server/infra/loadbalance.go
index 1ea23f996..eac8d6b26 100644
--- a/src/api/rest/server/infra/loadbalance.go
+++ b/src/api/rest/server/infra/loadbalance.go
@@ -15,7 +15,7 @@ limitations under the License.
 package infra
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -45,11 +45,11 @@ func RestPostNLB(c echo.Context) error {
 
 	u := &model.TbNLBReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := infra.CreateNLB(nsId, mciId, u, optionFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPostMcNLB godoc
@@ -73,11 +73,11 @@ func RestPostMcNLB(c echo.Context) error {
 
 	u := &model.TbNLBReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := infra.CreateMcSwNlb(nsId, mciId, u, "")
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 /*
@@ -127,7 +127,7 @@ func RestGetNLB(c echo.Context) error {
 	resourceId := c.Param("resourceId")
 
 	res, err := infra.GetNLB(nsId, mciId, resourceId)
-	return common.EndRequestWithLog(c, err, res)
+	return clientManager.EndRequestWithLog(c, err, res)
 }
 
 // Response structure for RestGetAllNLB
@@ -164,12 +164,12 @@ func RestGetAllNLB(c echo.Context) error {
 		content := model.IdList{}
 		var err error
 		content.IdList, err = infra.ListNLBId(nsId, mciId)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else {
 
 		resourceList, err := infra.ListNLB(nsId, mciId, filterKey, filterVal)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 
 		var content struct {
@@ -177,7 +177,7 @@ func RestGetAllNLB(c echo.Context) error {
 		}
 
 		content.NLB = resourceList.([]model.TbNLBInfo) // type assertion (interface{} -> array)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	}
 }
 
@@ -204,7 +204,7 @@ func RestDelNLB(c echo.Context) error {
 
 	err := infra.DelNLB(nsId, mciId, resourceId, forceFlag)
 	content := map[string]string{"message": "The NLB " + resourceId + " has been deleted"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestDelAllNLB godoc
@@ -229,7 +229,7 @@ func RestDelAllNLB(c echo.Context) error {
 	subString := c.QueryParam("match")
 
 	content, err := infra.DelAllNLB(nsId, mciId, subString, forceFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetNLBHealth godoc
@@ -253,7 +253,7 @@ func RestGetNLBHealth(c echo.Context) error {
 	resourceId := c.Param("resourceId")
 
 	content, err := infra.GetNLBHealth(nsId, mciId, resourceId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // The REST APIs below are for dev/test only
@@ -284,7 +284,7 @@ func RestAddNLBVMs(c echo.Context) error {
 		return err
 	}
 	content, err := infra.AddNLBVMs(nsId, mciId, resourceId, u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestRemoveNLBVMs godoc
@@ -314,5 +314,5 @@ func RestRemoveNLBVMs(c echo.Context) error {
 
 	err := infra.RemoveNLBVMs(nsId, mciId, resourceId, u)
 	content := map[string]string{"message": "Removed VMs from the NLB " + resourceId}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/infra/manageInfo.go b/src/api/rest/server/infra/manageInfo.go
index c4401bd31..97ab7cca8 100644
--- a/src/api/rest/server/infra/manageInfo.go
+++ b/src/api/rest/server/infra/manageInfo.go
@@ -17,7 +17,7 @@ package infra
 import (
 	"fmt"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -65,12 +65,12 @@ func RestGetMci(c echo.Context) error {
 		content := model.IdList{}
 		var err error
 		content.IdList, err = infra.ListVmByFilter(nsId, mciId, filterKey, filterVal)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else if option == "status" {
 
 		result, err := infra.GetMciStatus(nsId, mciId)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 
 		var content struct {
@@ -78,17 +78,17 @@ func RestGetMci(c echo.Context) error {
 		}
 		content.Result = result
 
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 
 	} else if option == "accessinfo" {
 
 		result, err := infra.GetMciAccessInfo(nsId, mciId, accessInfoOption)
-		return common.EndRequestWithLog(c, err, result)
+		return clientManager.EndRequestWithLog(c, err, result)
 
 	} else {
 
 		result, err := infra.GetMciInfo(nsId, mciId)
-		return common.EndRequestWithLog(c, err, result)
+		return clientManager.EndRequestWithLog(c, err, result)
 
 	}
 }
@@ -126,34 +126,34 @@ func RestGetAllMci(c echo.Context) error {
 		content := model.IdList{}
 		var err error
 		content.IdList, err = infra.ListMciId(nsId)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else if option == "status" {
 		// return MCI Status objects (diffent with MCI objects)
 		result, err := infra.ListMciStatus(nsId)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 		content := RestGetAllMciStatusResponse{}
 		content.Mci = result
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else if option == "simple" {
 		// MCI in simple (without VM information)
 		result, err := infra.ListMciInfo(nsId, option)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 		content := RestGetAllMciResponse{}
 		content.Mci = result
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else {
 		// MCI in detail (with status information)
 		result, err := infra.ListMciInfo(nsId, "status")
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 		content := RestGetAllMciResponse{}
 		content.Mci = result
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	}
 }
 
@@ -197,7 +197,7 @@ func RestDelMci(c echo.Context) error {
 	option := c.QueryParam("option")
 
 	content, err := infra.DelMci(nsId, mciId, option)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestDelAllMci godoc
@@ -219,7 +219,7 @@ func RestDelAllMci(c echo.Context) error {
 
 	message, err := infra.DelAllMci(nsId, option)
 	result := model.SimpleMsg{Message: message}
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // TODO: swag does not support multiple response types (success 200) in an API.
@@ -253,19 +253,19 @@ func RestGetMciVm(c echo.Context) error {
 	switch option {
 	case "status":
 		result, err := infra.GetMciVmStatus(nsId, mciId, vmId)
-		return common.EndRequestWithLog(c, err, result)
+		return clientManager.EndRequestWithLog(c, err, result)
 
 	case "idsInDetail":
 		result, err := infra.GetVmIdNameInDetail(nsId, mciId, vmId)
-		return common.EndRequestWithLog(c, err, result)
+		return clientManager.EndRequestWithLog(c, err, result)
 
 	case "accessinfo":
 		result, err := infra.GetMciVmAccessInfo(nsId, mciId, vmId, accessInfoOption)
-		return common.EndRequestWithLog(c, err, result)
+		return clientManager.EndRequestWithLog(c, err, result)
 
 	default:
 		result, err := infra.ListVmInfo(nsId, mciId, vmId)
-		return common.EndRequestWithLog(c, err, result)
+		return clientManager.EndRequestWithLog(c, err, result)
 	}
 }
 
@@ -315,11 +315,11 @@ func RestDelMciVm(c echo.Context) error {
 	if err != nil {
 		log.Error().Err(err).Msg("")
 		err := fmt.Errorf("Failed to delete the VM info")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result := map[string]string{"message": "Deleted the VM info"}
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestGetMciGroupVms godoc
@@ -347,7 +347,7 @@ func RestGetMciGroupVms(c echo.Context) error {
 	content := model.IdList{}
 	var err error
 	content.IdList, err = infra.ListVmBySubGroup(nsId, mciId, subgroupId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetMciGroupIds godoc
@@ -372,5 +372,5 @@ func RestGetMciGroupIds(c echo.Context) error {
 	content := model.IdList{}
 	var err error
 	content.IdList, err = infra.ListSubGroupId(nsId, mciId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/infra/monitoring.go b/src/api/rest/server/infra/monitoring.go
index c49460f50..72ee53e53 100644
--- a/src/api/rest/server/infra/monitoring.go
+++ b/src/api/rest/server/infra/monitoring.go
@@ -15,7 +15,7 @@ limitations under the License.
 package infra
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -42,11 +42,11 @@ func RestPostInstallMonitorAgentToMci(c echo.Context) error {
 
 	req := &model.MciCmdReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	// mciTmpSystemLabel := model.DefaultSystemLabel
 	content, err := infra.InstallMonitorAgentToMci(nsId, mciId, model.StrMCI, req)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPutMonitorAgentStatusInstalled godoc
@@ -72,11 +72,11 @@ func RestPutMonitorAgentStatusInstalled(c echo.Context) error {
 	// mciTmpSystemLabel := model.DefaultSystemLabel
 	err := infra.SetMonitoringAgentStatusInstalled(nsId, mciId, vmId)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.ListVmInfo(nsId, mciId, vmId)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestGetMonitorData godoc
@@ -101,9 +101,9 @@ func RestGetMonitorData(c echo.Context) error {
 
 	req := &model.MciCmdReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := infra.GetMonitoringData(nsId, mciId, metric)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/infra/orchestration.go b/src/api/rest/server/infra/orchestration.go
index 7827755b3..d9a65c61e 100644
--- a/src/api/rest/server/infra/orchestration.go
+++ b/src/api/rest/server/infra/orchestration.go
@@ -17,7 +17,7 @@ package infra
 import (
 	"fmt"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -45,11 +45,11 @@ func RestPostMciPolicy(c echo.Context) error {
 
 	req := &model.MciPolicyReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := infra.CreateMciPolicy(nsId, mciId, req)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetMciPolicy godoc
@@ -73,14 +73,14 @@ func RestGetMciPolicy(c echo.Context) error {
 	result, err := infra.GetMciPolicyObject(nsId, mciId)
 	if err != nil {
 		errorMessage := fmt.Errorf("Error to find MciPolicyObject : " + mciId + "ERROR : " + err.Error())
-		return common.EndRequestWithLog(c, errorMessage, nil)
+		return clientManager.EndRequestWithLog(c, errorMessage, nil)
 	}
 
 	if result.Id == "" {
 		errorMessage := fmt.Errorf("Failed to find MciPolicyObject : " + mciId)
-		return common.EndRequestWithLog(c, errorMessage, nil)
+		return clientManager.EndRequestWithLog(c, errorMessage, nil)
 	}
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // Response structure for RestGetAllMciPolicy
@@ -107,12 +107,12 @@ func RestGetAllMciPolicy(c echo.Context) error {
 
 	result, err := infra.GetAllMciPolicyObject(nsId)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content := RestGetAllMciPolicyResponse{}
 	content.MciPolicy = result
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 /*
@@ -154,7 +154,7 @@ func RestDelMciPolicy(c echo.Context) error {
 
 	err := infra.DelMciPolicy(nsId, mciId)
 	result := map[string]string{"message": "Deleted the MCI Policy info"}
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestDelAllMciPolicy godoc
@@ -172,5 +172,5 @@ func RestDelAllMciPolicy(c echo.Context) error {
 
 	nsId := c.Param("nsId")
 	result, err := infra.DelAllMciPolicy(nsId)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
diff --git a/src/api/rest/server/infra/provisioning.go b/src/api/rest/server/infra/provisioning.go
index f58eb28dd..e5c20d85e 100644
--- a/src/api/rest/server/infra/provisioning.go
+++ b/src/api/rest/server/infra/provisioning.go
@@ -17,7 +17,7 @@ package infra
 import (
 	"net/http"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -43,12 +43,12 @@ func RestPostMci(c echo.Context) error {
 
 	req := &model.TbMciReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	option := "create"
 	result, err := infra.CreateMci(nsId, req, option)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestPostRegisterCSPNativeVM godoc
@@ -70,12 +70,12 @@ func RestPostRegisterCSPNativeVM(c echo.Context) error {
 
 	req := &model.TbMciReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	option := "register"
 	result, err := infra.CreateMci(nsId, req, option)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestPostSystemMci godoc
@@ -96,11 +96,11 @@ func RestPostSystemMci(c echo.Context) error {
 
 	req := &model.TbMciDynamicReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.CreateSystemMciDynamic(option)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestPostMciDynamic godoc
@@ -127,13 +127,13 @@ func RestPostMciDynamic(c echo.Context) error {
 	req := &model.TbMciDynamicReq{}
 	if err := c.Bind(req); err != nil {
 		log.Warn().Err(err).Msg("invalid request")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.CreateMciDynamic(reqID, nsId, req, option)
 	if err != nil {
 		log.Error().Err(err).Msg("failed to create MCI dynamically")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	return c.JSON(http.StatusOK, result)
 }
@@ -159,11 +159,11 @@ func RestPostMciVmDynamic(c echo.Context) error {
 
 	req := &model.TbVmDynamicReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.CreateMciVmDynamic(nsId, mciId, req)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestPostMciDynamicCheckRequest godoc
@@ -182,11 +182,11 @@ func RestPostMciDynamicCheckRequest(c echo.Context) error {
 
 	req := &model.MciConnectionConfigCandidatesReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.CheckMciDynamicReq(req)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestPostMciVm godoc
@@ -210,10 +210,10 @@ func RestPostMciVm(c echo.Context) error {
 
 	vmInfoData := &model.TbVmReq{}
 	if err := c.Bind(vmInfoData); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	result, err := infra.CreateMciGroupVm(nsId, mciId, vmInfoData, true)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestPostMciSubGroupScaleOut godoc
@@ -239,9 +239,9 @@ func RestPostMciSubGroupScaleOut(c echo.Context) error {
 
 	scaleOutReq := &model.TbScaleOutSubGroupReq{}
 	if err := c.Bind(scaleOutReq); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.ScaleOutMciSubGroup(nsId, mciId, subgroupId, scaleOutReq.NumVMsToAdd)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
diff --git a/src/api/rest/server/infra/recommendation.go b/src/api/rest/server/infra/recommendation.go
index f48e71784..53176094a 100644
--- a/src/api/rest/server/infra/recommendation.go
+++ b/src/api/rest/server/infra/recommendation.go
@@ -15,7 +15,7 @@ limitations under the License.
 package infra
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -39,11 +39,11 @@ func RestRecommendVm(c echo.Context) error {
 
 	u := &model.DeploymentPlan{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := infra.RecommendVm(nsId, *u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 type RestPostMciRecommendResponse struct {
diff --git a/src/api/rest/server/infra/remoteCommand.go b/src/api/rest/server/infra/remoteCommand.go
index 7b8e61eea..7749cb8dc 100644
--- a/src/api/rest/server/infra/remoteCommand.go
+++ b/src/api/rest/server/infra/remoteCommand.go
@@ -20,6 +20,7 @@ import (
 	"net/http"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/labstack/echo/v4"
@@ -51,12 +52,12 @@ func RestPostCmdMci(c echo.Context) error {
 
 	req := &model.MciCmdReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	output, err := infra.RemoteCommandToMci(nsId, mciId, subGroupId, vmId, req)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result := model.MciSshCmdResult{}
@@ -69,7 +70,7 @@ func RestPostCmdMci(c echo.Context) error {
 
 	return c.JSON(http.StatusOK, result)
 
-	// return common.EndRequestWithLog(c, err, result)
+	// return clientManager.EndRequestWithLog(c, err, result)
 
 }
 
@@ -103,28 +104,28 @@ func RestPostFileToMci(c echo.Context) error {
 
 	if targetPath == "" {
 		err := fmt.Errorf("target path is required")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// Validate the file
 	file, err := c.FormFile("file")
 	if err != nil {
 		err = fmt.Errorf("failed to read the file %v", err)
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// File size validation
 	fileSizeLimit := int64(10 * 1024 * 1024) // (10MB limit)
 	if file.Size > fileSizeLimit {
 		err := fmt.Errorf("file too large, max size is %v", fileSizeLimit)
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// Open the file and read it into memory
 	src, err := file.Open()
 	if err != nil {
 		err = fmt.Errorf("failed to open the file %v", err)
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	defer src.Close()
 
@@ -132,18 +133,18 @@ func RestPostFileToMci(c echo.Context) error {
 	fileBytes, err := io.ReadAll(src)
 	if err != nil {
 		err = fmt.Errorf("failed to read the file %v", err)
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// Call the TransferFileToMci function
 	result, err := infra.TransferFileToMci(nsId, mciId, subGroupId, vmId, fileBytes, file.Filename, targetPath)
 	if err != nil {
 		err = fmt.Errorf("failed to transfer file to mci %v", err)
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// Return the result
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestSetBastionNodes godoc
@@ -169,7 +170,7 @@ func RestSetBastionNodes(c echo.Context) error {
 	bastionVmId := c.Param("bastionVmId")
 
 	content, err := infra.SetBastionNodes(nsId, mciId, targetVmId, bastionVmId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetBastionNodes godoc
@@ -193,7 +194,7 @@ func RestGetBastionNodes(c echo.Context) error {
 	targetVmId := c.Param("targetVmId")
 
 	content, err := infra.GetBastionNodes(nsId, mciId, targetVmId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestRemoveBastionNodes godoc
@@ -217,5 +218,5 @@ func RestRemoveBastionNodes(c echo.Context) error {
 	bastionVmId := c.Param("bastionVmId")
 
 	content, err := infra.RemoveBastionNodes(nsId, mciId, bastionVmId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/infra/utility.go b/src/api/rest/server/infra/utility.go
index 330751a01..c115746ff 100644
--- a/src/api/rest/server/infra/utility.go
+++ b/src/api/rest/server/infra/utility.go
@@ -15,7 +15,7 @@ limitations under the License.
 package infra
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/labstack/echo/v4"
 )
@@ -32,7 +32,7 @@ func RestCheckMci(c echo.Context) error {
 	}
 	content := JsonTemplate{}
 	content.Exists = exists
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 func RestCheckVm(c echo.Context) error {
@@ -48,5 +48,5 @@ func RestCheckVm(c echo.Context) error {
 	}
 	content := JsonTemplate{}
 	content.Exists = exists
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/middlewares/authmw/authmw.go b/src/api/rest/server/middlewares/authmw/authmw.go
index 0dbf95d93..4c4f59930 100644
--- a/src/api/rest/server/middlewares/authmw/authmw.go
+++ b/src/api/rest/server/middlewares/authmw/authmw.go
@@ -6,7 +6,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/go-resty/resty/v2"
 	"github.com/golang-jwt/jwt/v4"
 	echojwt "github.com/labstack/echo-jwt"
@@ -23,18 +23,18 @@ func InitJwtAuthMw(iamEndpoint string, pubkeyUrl string) error {
 
 	method := "GET"
 	url := fmt.Sprintf("%s/alive", iamEndpoint)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	var resReadyz map[string]string
 
-	err := common.ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&resReadyz,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
diff --git a/src/api/rest/server/middlewares/checkReadiness.go b/src/api/rest/server/middlewares/checkReadiness.go
index 06f15a0b3..f7ee7d181 100644
--- a/src/api/rest/server/middlewares/checkReadiness.go
+++ b/src/api/rest/server/middlewares/checkReadiness.go
@@ -3,7 +3,7 @@ package middlewares
 import (
 	"fmt"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/go-resty/resty/v2"
 	"github.com/labstack/echo/v4"
@@ -21,18 +21,18 @@ func CheckReadiness(url string, apiUser string, apiPass string) echo.MiddlewareF
 
 			// check readyz
 			method := "GET"
-			requestBody := common.NoBody
+			requestBody := clientManager.NoBody
 			resReadyz := new(model.Response)
 
-			err := common.ExecuteHttpRequest(
+			err := clientManager.ExecuteHttpRequest(
 				client,
 				method,
 				url,
 				nil,
-				common.SetUseBody(requestBody),
+				clientManager.SetUseBody(requestBody),
 				&requestBody,
 				resReadyz,
-				common.VeryShortDuration,
+				clientManager.VeryShortDuration,
 			)
 
 			if err != nil {
diff --git a/src/api/rest/server/middlewares/requestIdAndDetailsIssuer.go b/src/api/rest/server/middlewares/requestIdAndDetailsIssuer.go
index e453664a1..797963a6e 100644
--- a/src/api/rest/server/middlewares/requestIdAndDetailsIssuer.go
+++ b/src/api/rest/server/middlewares/requestIdAndDetailsIssuer.go
@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/labstack/echo/v4"
 )
 
@@ -24,19 +24,19 @@ func RequestIdAndDetailsIssuer(next echo.HandlerFunc) echo.HandlerFunc {
 		}
 
 		//log.Trace().Msgf("(Request ID middleware) Request ID: %s", reqID)
-		if _, ok := common.RequestMap.Load(reqID); ok {
+		if _, ok := clientManager.RequestMap.Load(reqID); ok {
 			return fmt.Errorf("the X-Request-Id is already in use")
 		}
 
 		// Set "X-Request-Id" in response header
 		c.Response().Header().Set(echo.HeaderXRequestID, reqID)
 
-		details := common.RequestDetails{
+		details := clientManager.RequestDetails{
 			StartTime:   time.Now(),
 			Status:      "Handling",
-			RequestInfo: common.ExtractRequestInfo(c.Request()),
+			RequestInfo: clientManager.ExtractRequestInfo(c.Request()),
 		}
-		common.RequestMap.Store(reqID, details)
+		clientManager.RequestMap.Store(reqID, details)
 
 		// log.Debug().Msg("End - Request ID middleware")
 
diff --git a/src/api/rest/server/middlewares/responseBodyDump.go b/src/api/rest/server/middlewares/responseBodyDump.go
index c06d6e763..80f12a3ee 100644
--- a/src/api/rest/server/middlewares/responseBodyDump.go
+++ b/src/api/rest/server/middlewares/responseBodyDump.go
@@ -5,7 +5,7 @@ import (
 	"encoding/json"
 	"time"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
 	"github.com/rs/zerolog/log"
@@ -36,14 +36,14 @@ func ResponseBodyDump() echo.MiddlewareFunc {
 			// Dump the response body if content type is "application/json" or "application/json; charset=UTF-8"
 			if contentType == echo.MIMEApplicationJSONCharsetUTF8 || contentType == echo.MIMEApplicationJSON {
 				// Load or check the request by ID
-				v, ok := common.RequestMap.Load(reqID)
+				v, ok := clientManager.RequestMap.Load(reqID)
 				if !ok {
 					log.Error().Msg("Request ID not found in common.RequestMap")
 					return
 				}
 
 				// Ensure the loaded value is of the correct type
-				details, ok := v.(common.RequestDetails)
+				details, ok := v.(clientManager.RequestDetails)
 				if !ok {
 					log.Error().Msg("Loaded value from common.RequestMap is not of type common.RequestDetails")
 					return
@@ -115,7 +115,7 @@ func ResponseBodyDump() echo.MiddlewareFunc {
 				}
 
 				// Store details of the request
-				common.RequestMap.Store(reqID, details)
+				clientManager.RequestMap.Store(reqID, details)
 			}
 			// log.Debug().Msg("Start - BodyDump() middleware")
 		},
diff --git a/src/api/rest/server/resource/common.go b/src/api/rest/server/resource/common.go
index 59640dcbe..297f73498 100644
--- a/src/api/rest/server/resource/common.go
+++ b/src/api/rest/server/resource/common.go
@@ -20,7 +20,7 @@ import (
 
 	"github.com/labstack/echo/v4"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 )
@@ -44,7 +44,7 @@ func RestDelAllResources(c echo.Context) error {
 	subString := c.QueryParam("match")
 
 	content, err := resource.DelAllResources(nsId, resourceType, subString, forceFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestDelResource is a common function to handle 'DelResource' REST API requests.
@@ -64,7 +64,7 @@ func RestDelResource(c echo.Context) error {
 
 	err := resource.DelResource(nsId, resourceType, resourceId, forceFlag)
 	content := map[string]string{"message": "The " + resourceType + " " + resourceId + " has been deleted"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // Todo: need to reimplment the following invalid function
@@ -92,7 +92,7 @@ func RestDelResource(c echo.Context) error {
 
 // 	err := model.DelChildResource(nsId, childResourceType, parentResourceId, childResourceId, forceFlag)
 // 	content := map[string]string{"message": "The " + childResourceType + " " + childResourceId + " has been deleted"}
-// 	return common.EndRequestWithLog(c, err, content)
+// 	return clientManager.EndRequestWithLog(c, err, content)
 // }
 
 // RestGetAllResources is a common function to handle 'GetAllResources' REST API requests.
@@ -112,13 +112,13 @@ func RestGetAllResources(c echo.Context) error {
 		content := model.IdList{}
 		var err error
 		content.IdList, err = resource.ListResourceId(nsId, resourceType)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else {
 
 		resourceList, err := resource.ListResource(nsId, resourceType, filterKey, filterVal)
 		if err != nil {
 			err := fmt.Errorf("Failed to list " + resourceType + "s; " + err.Error())
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 
 		switch resourceType {
@@ -128,52 +128,52 @@ func RestGetAllResources(c echo.Context) error {
 			}
 
 			content.Image = resourceList.([]model.TbImageInfo) // type assertion (interface{} -> array)
-			return common.EndRequestWithLog(c, err, content)
+			return clientManager.EndRequestWithLog(c, err, content)
 		case model.StrCustomImage:
 			var content struct {
 				Image []model.TbCustomImageInfo `json:"customImage"`
 			}
 
 			content.Image = resourceList.([]model.TbCustomImageInfo) // type assertion (interface{} -> array)
-			return common.EndRequestWithLog(c, err, content)
+			return clientManager.EndRequestWithLog(c, err, content)
 		case model.StrSecurityGroup:
 			var content struct {
 				SecurityGroup []model.TbSecurityGroupInfo `json:"securityGroup"`
 			}
 
 			content.SecurityGroup = resourceList.([]model.TbSecurityGroupInfo) // type assertion (interface{} -> array)
-			return common.EndRequestWithLog(c, err, content)
+			return clientManager.EndRequestWithLog(c, err, content)
 		case model.StrSpec:
 			var content struct {
 				Spec []model.TbSpecInfo `json:"spec"`
 			}
 
 			content.Spec = resourceList.([]model.TbSpecInfo) // type assertion (interface{} -> array)
-			return common.EndRequestWithLog(c, err, content)
+			return clientManager.EndRequestWithLog(c, err, content)
 		case model.StrSSHKey:
 			var content struct {
 				SshKey []model.TbSshKeyInfo `json:"sshKey"`
 			}
 
 			content.SshKey = resourceList.([]model.TbSshKeyInfo) // type assertion (interface{} -> array)
-			return common.EndRequestWithLog(c, err, content)
+			return clientManager.EndRequestWithLog(c, err, content)
 		case model.StrVNet:
 			var content struct {
 				VNet []model.TbVNetInfo `json:"vNet"`
 			}
 
 			content.VNet = resourceList.([]model.TbVNetInfo) // type assertion (interface{} -> array)
-			return common.EndRequestWithLog(c, err, content)
+			return clientManager.EndRequestWithLog(c, err, content)
 		case model.StrDataDisk:
 			var content struct {
 				DataDisk []model.TbDataDiskInfo `json:"dataDisk"`
 			}
 
 			content.DataDisk = resourceList.([]model.TbDataDiskInfo) // type assertion (interface{} -> array)
-			return common.EndRequestWithLog(c, err, content)
+			return clientManager.EndRequestWithLog(c, err, content)
 		default:
 			err := fmt.Errorf("Not accepatble resourceType: " + resourceType)
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 
 		}
 	}
@@ -196,9 +196,9 @@ func RestGetResource(c echo.Context) error {
 	result, err := resource.GetResource(nsId, resourceType, resourceId)
 	if err != nil {
 		errorMessage := fmt.Errorf("Failed to find " + resourceType + " " + resourceId)
-		return common.EndRequestWithLog(c, errorMessage, nil)
+		return clientManager.EndRequestWithLog(c, errorMessage, nil)
 	}
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestCheckResource godoc
@@ -230,7 +230,7 @@ func RestCheckResource(c echo.Context) error {
 	content := JsonTemplate{}
 	content.Exists = exists
 
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestTestAddObjectAssociation is a REST API call handling function
@@ -247,7 +247,7 @@ func RestTestAddObjectAssociation(c echo.Context) error {
 
 	content, err := resource.UpdateAssociatedObjectList(nsId, resourceType, resourceId, model.StrAdd, "/test/vm/key")
 
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestTestDeleteObjectAssociation is a REST API call handling function
@@ -263,7 +263,7 @@ func RestTestDeleteObjectAssociation(c echo.Context) error {
 	resourceId = strings.ReplaceAll(resourceId, "%2B", "+")
 
 	content, err := resource.UpdateAssociatedObjectList(nsId, resourceType, resourceId, model.StrDelete, "/test/vm/key")
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestTestGetAssociatedObjectCount is a REST API call handling function
@@ -281,7 +281,7 @@ func RestTestGetAssociatedObjectCount(c echo.Context) error {
 	associatedObjectCount, err := resource.GetAssociatedObjectCount(nsId, resourceType, resourceId)
 	content := map[string]int{"associatedObjectCount": associatedObjectCount}
 
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestLoadAssets godoc
@@ -297,7 +297,7 @@ func RestTestGetAssociatedObjectCount(c echo.Context) error {
 func RestLoadAssets(c echo.Context) error {
 
 	content, err := resource.LoadAssets()
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestCreateSharedResource godoc
@@ -323,7 +323,7 @@ func RestCreateSharedResource(c echo.Context) error {
 
 	err := resource.CreateSharedResource(nsId, resType, connectionName)
 	content := map[string]string{"message": "Done"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestDelAllSharedResources godoc
@@ -342,7 +342,7 @@ func RestDelAllSharedResources(c echo.Context) error {
 	nsId := c.Param("nsId")
 
 	content, err := resource.DelAllSharedResources(nsId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 /*
diff --git a/src/api/rest/server/resource/customimage.go b/src/api/rest/server/resource/customimage.go
index 0192ea678..027425b0d 100644
--- a/src/api/rest/server/resource/customimage.go
+++ b/src/api/rest/server/resource/customimage.go
@@ -17,7 +17,7 @@ package resource
 import (
 	"fmt"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 	"github.com/labstack/echo/v4"
@@ -45,16 +45,16 @@ func RestPostCustomImage(c echo.Context) error {
 
 	if optionFlag != "register" {
 		err := fmt.Errorf("POST customImage can be called only with 'option=register'")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	u := &model.TbCustomImageReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.RegisterCustomImageWithId(nsId, u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetCustomImage godoc
diff --git a/src/api/rest/server/resource/dataDisk.go b/src/api/rest/server/resource/dataDisk.go
index 1444fdd1b..6a39a045c 100644
--- a/src/api/rest/server/resource/dataDisk.go
+++ b/src/api/rest/server/resource/dataDisk.go
@@ -18,7 +18,7 @@ import (
 	"fmt"
 	"strconv"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
@@ -47,11 +47,11 @@ func RestPostDataDisk(c echo.Context) error {
 
 	u := &model.TbDataDiskReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.CreateDataDisk(nsId, u, optionFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPutDataDisk godoc
@@ -75,11 +75,11 @@ func RestPutDataDisk(c echo.Context) error {
 
 	u := &model.TbDataDiskUpsizeReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.UpsizeDataDisk(nsId, dataDiskId, u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetDataDisk godoc
@@ -189,13 +189,13 @@ func RestPutVmDataDisk(c echo.Context) error {
 	if forceStr != "" {
 		forceBool, err = strconv.ParseBool(forceStr)
 		if err != nil {
-			return common.EndRequestWithLog(c, fmt.Errorf("Invalid force value: %s", forceStr), nil)
+			return clientManager.EndRequestWithLog(c, fmt.Errorf("Invalid force value: %s", forceStr), nil)
 		}
 	}
 
 	u := &model.TbAttachDetachDataDiskReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	switch option {
@@ -203,11 +203,11 @@ func RestPutVmDataDisk(c echo.Context) error {
 		fallthrough
 	case model.DetachDataDisk:
 		result, err := infra.AttachDetachDataDisk(nsId, mciId, vmId, option, u.DataDiskId, forceBool)
-		return common.EndRequestWithLog(c, err, result)
+		return clientManager.EndRequestWithLog(c, err, result)
 
 	default:
 		err := fmt.Errorf("Supported options: %s, %s, %s", model.AttachDataDisk, model.DetachDataDisk, model.AvailableDataDisk)
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 }
 
@@ -233,15 +233,15 @@ func RestPostVmDataDisk(c echo.Context) error {
 
 	u := &model.TbDataDiskVmReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.ProvisionDataDisk(nsId, mciId, vmId, u)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestGetVmDataDisk godoc
@@ -267,7 +267,7 @@ func RestGetVmDataDisk(c echo.Context) error {
 
 	result, err := infra.GetAvailableDataDisks(nsId, mciId, vmId, optionFlag)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	var content interface{}
@@ -281,5 +281,5 @@ func RestGetVmDataDisk(c echo.Context) error {
 		}
 	}
 
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/resource/firewallrule.go b/src/api/rest/server/resource/firewallrule.go
index cd1cf24bd..1232695f4 100644
--- a/src/api/rest/server/resource/firewallrule.go
+++ b/src/api/rest/server/resource/firewallrule.go
@@ -15,7 +15,7 @@ limitations under the License.
 package resource
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 	"github.com/labstack/echo/v4"
@@ -46,11 +46,11 @@ func RestPostFirewallRules(c echo.Context) error {
 
 	u := &TbFirewallRulesWrapper{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.CreateFirewallRules(nsId, securityGroupId, *&u.FirewallRules, false)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 /* function RestPutFirewallRules not yet implemented
@@ -119,9 +119,9 @@ func RestDelFirewallRules(c echo.Context) error {
 
 	u := &TbFirewallRulesWrapper{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.DeleteFirewallRules(nsId, securityGroupId, *&u.FirewallRules)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/resource/image.go b/src/api/rest/server/resource/image.go
index 061c73506..dd050ef67 100644
--- a/src/api/rest/server/resource/image.go
+++ b/src/api/rest/server/resource/image.go
@@ -19,7 +19,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 	"github.com/labstack/echo/v4"
@@ -65,21 +65,21 @@ func RestPostImage(c echo.Context) error {
 		log.Debug().Msg("[Registering Image with info]")
 		u := &model.TbImageInfo{}
 		if err := c.Bind(u); err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 		content, err := resource.RegisterImageWithInfo(nsId, u, update)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else if action == "registerWithId" {
 		log.Debug().Msg("[Registering Image with ID]")
 		u := &model.TbImageReq{}
 		if err := c.Bind(u); err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 		content, err := resource.RegisterImageWithId(nsId, u, update, false)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 	} else {
 		err := fmt.Errorf("You must specify: action=registerWithInfo or action=registerWithId")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 }
@@ -107,11 +107,11 @@ func RestPutImage(c echo.Context) error {
 
 	u := &model.TbImageInfo{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.UpdateImage(nsId, resourceId, *u, false)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // Request structure for RestLookupImage
@@ -136,12 +136,12 @@ func RestLookupImage(c echo.Context) error {
 
 	u := &RestLookupImageRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	log.Debug().Msg("[Lookup image]: " + u.CspImageName)
 	content, err := resource.LookupImage(u.ConnectionName, u.CspImageName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -161,12 +161,12 @@ func RestLookupImageList(c echo.Context) error {
 
 	u := &RestLookupImageRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	log.Debug().Msg("[Lookup images]")
 	content, err := resource.LookupImageList(u.ConnectionName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -188,7 +188,7 @@ func RestFetchImages(c echo.Context) error {
 
 	u := &RestLookupImageRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	var connConfigCount, imageCount uint
@@ -197,19 +197,19 @@ func RestFetchImages(c echo.Context) error {
 	if u.ConnectionName == "" {
 		connConfigCount, imageCount, err = resource.FetchImagesForAllConnConfigs(nsId)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 	} else {
 		connConfigCount = 1
 		imageCount, err = resource.FetchImagesForConnConfig(u.ConnectionName, nsId)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 	}
 
 	content := map[string]string{
 		"message": "Fetched " + fmt.Sprint(imageCount) + " images (from " + fmt.Sprint(connConfigCount) + " connConfigs)"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetImage godoc
@@ -232,7 +232,7 @@ func RestGetImage(c echo.Context) error {
 	imageKey = strings.ReplaceAll(imageKey, "%2B", "+")
 
 	content, err := resource.GetImage(nsId, imageKey)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // Response structure for RestGetAllImage
@@ -324,5 +324,5 @@ func RestSearchImage(c echo.Context) error {
 	content, err := resource.SearchImage(nsId, u.Keywords...)
 	result := RestGetAllImageResponse{}
 	result.Image = content
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
diff --git a/src/api/rest/server/resource/k8scluster.go b/src/api/rest/server/resource/k8scluster.go
index 584d4242b..f42b88cd0 100644
--- a/src/api/rest/server/resource/k8scluster.go
+++ b/src/api/rest/server/resource/k8scluster.go
@@ -19,6 +19,7 @@ import (
 	"net/http"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/infra"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
@@ -46,7 +47,7 @@ func RestGetAvailableK8sVersion(c echo.Context) error {
 	regionName := c.QueryParam("regionName")
 
 	content, err := common.GetAvailableK8sVersion(providerName, regionName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetAvailableK8sNodeImage func is a rest api wrapper for GetAvailableK8sNodeImage.
@@ -69,7 +70,7 @@ func RestGetAvailableK8sNodeImage(c echo.Context) error {
 	regionName := c.QueryParam("regionName")
 
 	content, err := common.GetAvailableK8sNodeImage(providerName, regionName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestCheckK8sNodeGroupsOnK8sCreation func is a rest api wrapper for GetModelK8sNodeGroupsOnK8sCreation.
@@ -90,7 +91,7 @@ func RestCheckK8sNodeGroupsOnK8sCreation(c echo.Context) error {
 	providerName := c.QueryParam("providerName")
 
 	content, err := common.GetModelK8sNodeGroupsOnK8sCreation(providerName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestCheckK8sNodeImageDesignation func is a rest api wrapper for GetK8sNodeImageDesignation.
@@ -111,7 +112,7 @@ func RestCheckK8sNodeImageDesignation(c echo.Context) error {
 	providerName := c.QueryParam("providerName")
 
 	content, err := common.GetModelK8sNodeImageDesignation(providerName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetRequiredK8sSubnetCount func is a rest api wrapper for GetModelK8sRequiredSubnetCount.
@@ -132,7 +133,7 @@ func RestGetRequiredK8sSubnetCount(c echo.Context) error {
 	providerName := c.QueryParam("providerName")
 
 	content, err := common.GetModelK8sRequiredSubnetCount(providerName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPostK8sCluster func is a rest api wrapper for CreateK8sCluster.
@@ -561,11 +562,11 @@ func RestPostK8sClusterDynamicCheckRequest(c echo.Context) error {
 
 	req := &model.K8sClusterConnectionConfigCandidatesReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.CheckK8sClusterDynamicReq(req)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestPostK8sClusterDynamic godoc
@@ -592,13 +593,13 @@ func RestPostK8sClusterDynamic(c echo.Context) error {
 	req := &model.TbK8sClusterDynamicReq{}
 	if err := c.Bind(req); err != nil {
 		log.Warn().Err(err).Msg("invalid request")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	result, err := infra.CreateK8sClusterDynamic(reqID, nsId, req, optionFlag)
 	if err != nil {
 		log.Error().Err(err).Msg("failed to create K8sCluster dynamically")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	return c.JSON(http.StatusOK, result)
 }
@@ -627,14 +628,14 @@ func RestPostK8sNodeGroupDynamic(c echo.Context) error {
 	req := &model.TbK8sNodeGroupDynamicReq{}
 	if err := c.Bind(req); err != nil {
 		log.Warn().Err(err).Msg("invalid request")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	log.Debug().Msgf("reqID: %s, nsId: %s, k8sClusterId: %s, req: %v\n", reqID, nsId, k8sClusterId, req)
 	result, err := infra.CreateK8sNodeGroupDynamic(reqID, nsId, k8sClusterId, req)
 	if err != nil {
 		log.Error().Err(err).Msg("failed to create K8sNodeGroup dynamically")
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 	return c.JSON(http.StatusOK, result)
 }
@@ -665,14 +666,14 @@ func RestGetControlK8sCluster(c echo.Context) error {
 
 		resultString, err := resource.HandleK8sClusterAction(nsId, k8sClusterId, action)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, returnObj)
+			return clientManager.EndRequestWithLog(c, err, returnObj)
 		}
 		returnObj.Message = resultString
-		return common.EndRequestWithLog(c, err, returnObj)
+		return clientManager.EndRequestWithLog(c, err, returnObj)
 
 	} else {
 		err := fmt.Errorf("'action' should be one of these: continue, withdraw")
-		return common.EndRequestWithLog(c, err, returnObj)
+		return clientManager.EndRequestWithLog(c, err, returnObj)
 	}
 }
 
@@ -694,19 +695,19 @@ func RestRecommendK8sNode(c echo.Context) error {
 
 	u := &model.DeploymentPlan{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := infra.RecommendK8sNode(nsId, *u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPostCmdK8sCluster godoc
 // @ID PostCmdK8sCluster
 // @Summary Send a command to specified Container in K8sCluster
 // @Description Send a command to specified Container in K8sCluster
-// @Description [note] This feature is not intended for general use 
-// @Description This API is provided as an exceptional and limited function for specific purposes such as migration. 
+// @Description [note] This feature is not intended for general use
+// @Description This API is provided as an exceptional and limited function for specific purposes such as migration.
 // @Description Kubernetes resource information required as input for this API is not currently provided, and its availability in the future is uncertain.
 // @Tags [Kubernetes] Cluster's Container Remote Command
 // @Accept  json
@@ -732,9 +733,9 @@ func RestPostCmdK8sCluster(c echo.Context) error {
 
 	req := &model.TbK8sClusterContainerCmdReq{}
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.RemoteCommandToK8sClusterContainer(nsId, k8sClusterId, k8sClusterNamespace, k8sClusterPodName, k8sClusterContainerName, req)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
diff --git a/src/api/rest/server/resource/securitygroup.go b/src/api/rest/server/resource/securitygroup.go
index 20a28881b..ca8ffbaf4 100644
--- a/src/api/rest/server/resource/securitygroup.go
+++ b/src/api/rest/server/resource/securitygroup.go
@@ -15,7 +15,7 @@ limitations under the License.
 package resource
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 	"github.com/labstack/echo/v4"
@@ -43,11 +43,11 @@ func RestPostSecurityGroup(c echo.Context) error {
 
 	u := &model.TbSecurityGroupReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.CreateSecurityGroup(nsId, u, optionFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 /*
diff --git a/src/api/rest/server/resource/spec.go b/src/api/rest/server/resource/spec.go
index a71544c14..4d2fc9ace 100644
--- a/src/api/rest/server/resource/spec.go
+++ b/src/api/rest/server/resource/spec.go
@@ -19,7 +19,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 	"github.com/labstack/echo/v4"
@@ -58,19 +58,19 @@ func RestPostSpec(c echo.Context) error {
 		log.Debug().Msg("[Registering Spec with info]")
 		u := &model.TbSpecInfo{}
 		if err := c.Bind(u); err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 		content, err := resource.RegisterSpecWithInfo(nsId, u, update)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 
 	} else { // if action == "registerWithCspResourceId" { // The default mode.
 		log.Debug().Msg("[Registering Spec with cspSpecName]")
 		u := &model.TbSpecReq{}
 		if err := c.Bind(u); err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 		content, err := resource.RegisterSpecWithCspResourceId(nsId, u, update)
-		return common.EndRequestWithLog(c, err, content)
+		return clientManager.EndRequestWithLog(c, err, content)
 
 	} /* else {
 		mapA := map[string]string{"message": "LookupSpec(specRequest) failed."}
@@ -102,11 +102,11 @@ func RestPutSpec(c echo.Context) error {
 
 	u := &model.TbSpecInfo{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.UpdateSpec(nsId, specId, *u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // Request structure for RestLookupSpec
@@ -131,12 +131,12 @@ func RestLookupSpec(c echo.Context) error {
 
 	u := &RestLookupSpecRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	fmt.Println("[Lookup spec]: " + u.CspResourceId)
 	content, err := resource.LookupSpec(u.ConnectionName, u.CspResourceId)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -156,12 +156,12 @@ func RestLookupSpecList(c echo.Context) error {
 
 	u := &RestLookupSpecRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	log.Debug().Msg("[Lookup specs]")
 	content, err := resource.LookupSpecList(u.ConnectionName)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 
 }
 
@@ -183,7 +183,7 @@ func RestFetchSpecs(c echo.Context) error {
 
 	u := &RestLookupSpecRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	var connConfigCount, specCount uint
@@ -192,19 +192,19 @@ func RestFetchSpecs(c echo.Context) error {
 	if u.ConnectionName == "" {
 		connConfigCount, specCount, err = resource.FetchSpecsForAllConnConfigs(nsId)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 	} else {
 		connConfigCount = 1
 		specCount, err = resource.FetchSpecsForConnConfig(u.ConnectionName, nsId)
 		if err != nil {
-			return common.EndRequestWithLog(c, err, nil)
+			return clientManager.EndRequestWithLog(c, err, nil)
 		}
 	}
 
 	content := map[string]string{
 		"message": "Fetched " + fmt.Sprint(specCount) + " specs (from " + fmt.Sprint(connConfigCount) + " connConfigs)"}
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestFilterSpecsResponse is Response structure for RestFilterSpecs
@@ -231,14 +231,14 @@ func RestFilterSpecsByRange(c echo.Context) error {
 
 	u := &model.FilterSpecsByRangeRequest{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	log.Debug().Msg("[Filter specs]")
 	content, err := resource.FilterSpecsByRange(nsId, *u)
 	result := RestFilterSpecsResponse{}
 	result.Spec = content
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestGetSpec godoc
@@ -264,7 +264,7 @@ func RestGetSpec(c echo.Context) error {
 
 	log.Debug().Msg("[Get spec]" + specId)
 	result, err := resource.GetSpec(nsId, specId)
-	return common.EndRequestWithLog(c, err, result)
+	return clientManager.EndRequestWithLog(c, err, result)
 }
 
 // RestDelSpec godoc
diff --git a/src/api/rest/server/resource/sshkey.go b/src/api/rest/server/resource/sshkey.go
index 96cf62f2f..4c242b757 100644
--- a/src/api/rest/server/resource/sshkey.go
+++ b/src/api/rest/server/resource/sshkey.go
@@ -15,7 +15,7 @@ limitations under the License.
 package resource
 
 import (
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 	"github.com/labstack/echo/v4"
@@ -43,11 +43,11 @@ func RestPostSshKey(c echo.Context) error {
 
 	u := &model.TbSshKeyReq{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.CreateSshKey(nsId, u, optionFlag)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestPutSshKey godoc
@@ -71,11 +71,11 @@ func RestPutSshKey(c echo.Context) error {
 
 	u := &model.TbSshKeyInfo{}
 	if err := c.Bind(u); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	content, err := resource.UpdateSshKey(nsId, sshKeyId, *u)
-	return common.EndRequestWithLog(c, err, content)
+	return clientManager.EndRequestWithLog(c, err, content)
 }
 
 // RestGetSshKey godoc
diff --git a/src/api/rest/server/util/netuil.go b/src/api/rest/server/util/netuil.go
index 69128e886..8333b1b5e 100644
--- a/src/api/rest/server/util/netuil.go
+++ b/src/api/rest/server/util/netuil.go
@@ -3,7 +3,7 @@ package netutil
 import (
 	"net/http"
 
-	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/netutil"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
@@ -76,16 +76,16 @@ func RestPostUtilToDesignNetwork(c echo.Context) error {
 	// Bind the request body to SubnettingRequest struct
 	subnettingReq := new(netutil.SubnettingRequest)
 	if err := c.Bind(subnettingReq); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// Subnetting as many as requested rules
 	networkConfig, err := netutil.SubnettingBy(*subnettingReq)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
-	return common.EndRequestWithLog(c, err, networkConfig)
+	return clientManager.EndRequestWithLog(c, err, networkConfig)
 }
 
 type RestPostUtilToValidateNetworkRequest struct {
@@ -109,18 +109,18 @@ func RestPostUtilToValidateNetwork(c echo.Context) error {
 	// Bind the request body to SubnettingRequest struct
 	req := new(netutil.NetworkConfig)
 	if err := c.Bind(req); err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	// Validate the network configuration
 	netConf := req.NetworkConfiguration
 	err := netutil.ValidateNetwork(netConf)
 	if err != nil {
-		return common.EndRequestWithLog(c, err, nil)
+		return clientManager.EndRequestWithLog(c, err, nil)
 	}
 
 	okMessage := model.SimpleMsg{}
 	okMessage.Message = "Network configuration is valid."
 
-	return common.EndRequestWithLog(c, err, okMessage)
+	return clientManager.EndRequestWithLog(c, err, okMessage)
 }
diff --git a/src/core/common/client.go b/src/core/common/client/client.go
similarity index 99%
rename from src/core/common/client.go
rename to src/core/common/client/client.go
index 1c3c159cd..5f192d2f4 100644
--- a/src/core/common/client.go
+++ b/src/core/common/client/client.go
@@ -11,8 +11,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// Package common is to include common methods for managing multi-cloud infra
-package common
+// Package client is to manage internal HTTP requests and caching
+package client
 
 import (
 	"bytes"
diff --git a/src/core/common/label/label.go b/src/core/common/label/label.go
index a82cca462..38f231ed0 100644
--- a/src/core/common/label/label.go
+++ b/src/core/common/label/label.go
@@ -23,6 +23,7 @@ import (
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvutil"
 	"github.com/rs/zerolog/log"
+	// "github.com/go-resty/resty/v2"
 )
 
 // CreateOrUpdateLabel adds a new label or updates an existing label for the given resource,
@@ -304,3 +305,40 @@ func GetResourcesByLabelSelector(labelType, labelSelector string) ([]interface{}
 	//log.Debug().Int("numMatchedResources", len(matchedResources)).Str("labelType", labelType).Msg("Matched resources found")
 	return matchedResources, nil
 }
+
+// func UpdateCSPResourceLabel(cspType string, resourceKey string, labels map[string]string) error {
+
+// 	driverName := RuntimeCloudInfo.CSPs[providerName].Driver
+
+// 	client := resty.New()
+// 	url := model.SpiderRestUrl + "/driver"
+// 	method := "POST"
+// 	var callResult model.CloudDriverInfo
+// 	requestBody := model.CloudDriverInfo{ProviderName: strings.ToUpper(providerName), DriverName: driverName, DriverLibFileName: driverName}
+
+// 	err := ExecuteHttpRequest(
+// 		client,
+// 		method,
+// 		url,
+// 		nil,
+// 		SetUseBody(requestBody),
+// 		&requestBody,
+// 		&callResult,
+// 		MediumDuration,
+// 	)
+
+// 	if err != nil {
+// 		log.Error().Err(err).Msg("")
+// 		return err
+// 	}
+
+// 	for regionName, _ := range RuntimeCloudInfo.CSPs[providerName].Regions {
+// 		err := RegisterRegionZone(providerName, regionName)
+// 		if err != nil {
+// 			log.Error().Err(err).Msg("")
+// 			return err
+// 		}
+// 	}
+
+// 	return nil
+// }
diff --git a/src/core/common/utility.go b/src/core/common/utility.go
index 5de77458c..963796649 100644
--- a/src/core/common/utility.go
+++ b/src/core/common/utility.go
@@ -32,6 +32,7 @@ import (
 	"encoding/base64"
 	"encoding/pem"
 
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvutil"
@@ -296,15 +297,15 @@ func CheckConnConfigAvailable(connConfigName string) (bool, error) {
 	requestBody := model.SpiderConnectionName{}
 	requestBody.ConnectionName = connConfigName
 
-	err := ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		ShortDuration,
+		clientManager.ShortDuration,
 	)
 
 	if err != nil {
@@ -322,17 +323,17 @@ func CheckSpiderReady() error {
 	client := resty.New()
 	url := model.SpiderRestUrl + "/readyz"
 	method := "GET"
-	requestBody := NoBody
+	requestBody := clientManager.NoBody
 
-	err := ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -437,15 +438,15 @@ func RegisterCloudInfo(providerName string) error {
 	var callResult model.CloudDriverInfo
 	requestBody := model.CloudDriverInfo{ProviderName: strings.ToUpper(providerName), DriverName: driverName, DriverLibFileName: driverName}
 
-	err := ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -489,15 +490,15 @@ func RegisterRegionZone(providerName string, regionName string) error {
 	}
 	requestBody.KeyValueInfoList = keyValueInfoList
 
-	err := ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -515,15 +516,15 @@ func RegisterRegionZone(providerName string, regionName string) error {
 		requestBody.AvailableZoneList = RuntimeCloudInfo.CSPs[providerName].Regions[regionName].Zones
 		requestBody.KeyValueInfoList = keyValueInfoList
 
-		err := ExecuteHttpRequest(
+		err := clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			&callResult,
-			MediumDuration,
+			clientManager.MediumDuration,
 		)
 
 		if err != nil {
@@ -676,15 +677,15 @@ func RegisterCredential(req model.CredentialReq) (model.CredentialInfo, error) {
 
 	//PrintJsonPretty(requestBody)
 
-	err = ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -900,15 +901,15 @@ func RegisterConnectionConfig(connConfig model.ConnConfig) (model.ConnConfig, er
 	requestBody.CredentialName = connConfig.CredentialName
 	requestBody.RegionName = connConfig.RegionZoneInfoName
 
-	err := ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -948,17 +949,17 @@ func RegisterConnectionConfig(connConfig model.ConnConfig) (model.ConnConfig, er
 	url = model.SpiderRestUrl + "/region/" + connection.RegionZoneInfoName
 	method = "GET"
 	var callResultRegion model.SpiderRegionZoneInfo
-	requestNoBody := NoBody
+	requestNoBody := clientManager.NoBody
 
-	err = ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		SetUseBody(requestNoBody),
+		clientManager.SetUseBody(requestNoBody),
 		&requestNoBody,
 		&callResultRegion,
-		MediumDuration,
+		clientManager.MediumDuration,
 	)
 	if err != nil {
 		log.Error().Err(err).Msg("")
diff --git a/src/core/infra/control.go b/src/core/infra/control.go
index d261a8b6e..4b37dbfcc 100644
--- a/src/core/infra/control.go
+++ b/src/core/infra/control.go
@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
@@ -439,15 +440,15 @@ func ControlVmAsync(wg *sync.WaitGroup, nsId string, mciId string, vmId string,
 			requestBody := model.SpiderConnectionName{}
 			requestBody.ConnectionName = temp.ConnectionName
 
-			err = common.ExecuteHttpRequest(
+			err = clientManager.ExecuteHttpRequest(
 				client,
 				method,
 				url,
 				nil,
-				common.SetUseBody(requestBody),
+				clientManager.SetUseBody(requestBody),
 				&requestBody,
 				&callResult,
-				common.MediumDuration,
+				clientManager.MediumDuration,
 			)
 			if err != nil {
 				log.Error().Err(err).Msg("")
diff --git a/src/core/infra/manageInfo.go b/src/core/infra/manageInfo.go
index a2ecf9307..8d2243da2 100644
--- a/src/core/infra/manageInfo.go
+++ b/src/core/infra/manageInfo.go
@@ -28,6 +28,7 @@ import (
 	"sync"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
@@ -789,15 +790,15 @@ func GetVmIdNameInDetail(nsId string, mciId string, vmId string) (*model.TbIdNam
 	method := "GET"
 	client.SetTimeout(5 * time.Minute)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -1068,15 +1069,15 @@ func GetVmCurrentPublicIp(nsId string, mciId string, vmId string) (model.TbVmSta
 	requestBody.ConnectionName = temp.ConnectionName
 	callResult := statusResponse{}
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -1202,15 +1203,15 @@ func FetchVmStatus(nsId string, mciId string, vmId string) (model.TbVmStatusInfo
 		retrycheck := 2
 		for i := 0; i < retrycheck; i++ {
 			errorInfo.Status = model.StatusFailed
-			err := common.ExecuteHttpRequest(
+			err := clientManager.ExecuteHttpRequest(
 				client,
 				method,
 				url,
 				nil,
-				common.SetUseBody(requestBody),
+				clientManager.SetUseBody(requestBody),
 				&requestBody,
 				&callResult,
-				common.MediumDuration,
+				clientManager.MediumDuration,
 			)
 			if err != nil {
 				errorInfo.SystemMessage = err.Error()
@@ -1553,15 +1554,15 @@ func AttachDetachDataDisk(nsId string, mciId string, vmId string, command string
 
 	}
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -1607,15 +1608,15 @@ func AttachDetachDataDisk(nsId string, mciId string, vmId string, command string
 	}
 	var callResultSpiderVMInfo model.SpiderVMInfo
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBodyConnection),
+		clientManager.SetUseBody(requestBodyConnection),
 		&requestBodyConnection,
 		&callResultSpiderVMInfo,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/infra/provisioning.go b/src/core/infra/provisioning.go
index f18a26250..03225190e 100644
--- a/src/core/infra/provisioning.go
+++ b/src/core/infra/provisioning.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/core/resource"
@@ -1029,11 +1030,11 @@ func CreateMciDynamic(reqID string, nsId string, req *model.TbMciDynamicReq, dep
 
 	// Log the prepared MCI request and update the progress
 	common.PrintJsonPretty(mciReq)
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{
 		Title: "Prepared all resources for provisioning MCI: " + mciReq.Name,
 		Info:  mciReq, Time: time.Now(),
 	})
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{
 		Title: "Start instance provisioning", Time: time.Now(),
 	})
 
@@ -1164,7 +1165,7 @@ func getVmReqFromDynamicReq(reqID string, nsId string, req *model.TbVmDynamicReq
 		}
 	}
 
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Setting vNet:" + resourceName, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Setting vNet:" + resourceName, Time: time.Now()})
 
 	vmReq.VNetId = resourceName
 	_, err = resource.GetResource(nsId, model.StrVNet, vmReq.VNetId)
@@ -1174,7 +1175,7 @@ func getVmReqFromDynamicReq(reqID string, nsId string, req *model.TbVmDynamicReq
 			log.Error().Err(err).Msg("Failed to get the vNet")
 			return &model.TbVmReq{}, err
 		}
-		common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Loading default vNet:" + resourceName, Time: time.Now()})
+		clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Loading default vNet:" + resourceName, Time: time.Now()})
 
 		// Check if the default vNet exists
 		_, err := resource.GetResource(nsId, model.StrVNet, vmReq.ConnectionName)
@@ -1194,7 +1195,7 @@ func getVmReqFromDynamicReq(reqID string, nsId string, req *model.TbVmDynamicReq
 	}
 	vmReq.SubnetId = resourceName
 
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Setting SSHKey:" + resourceName, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Setting SSHKey:" + resourceName, Time: time.Now()})
 	vmReq.SshKeyId = resourceName
 	_, err = resource.GetResource(nsId, model.StrSSHKey, vmReq.SshKeyId)
 	if err != nil {
@@ -1203,7 +1204,7 @@ func getVmReqFromDynamicReq(reqID string, nsId string, req *model.TbVmDynamicReq
 			log.Error().Err(err).Msg("Failed to get the SSHKey")
 			return &model.TbVmReq{}, err
 		}
-		common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Loading default SSHKey:" + resourceName, Time: time.Now()})
+		clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Loading default SSHKey:" + resourceName, Time: time.Now()})
 
 		// Check if the default SSHKey exists
 		_, err := resource.GetResource(nsId, model.StrSSHKey, vmReq.ConnectionName)
@@ -1222,7 +1223,7 @@ func getVmReqFromDynamicReq(reqID string, nsId string, req *model.TbVmDynamicReq
 		log.Info().Msg("Found and utilize default SSHKey: " + vmReq.VNetId)
 	}
 
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Setting securityGroup:" + resourceName, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Setting securityGroup:" + resourceName, Time: time.Now()})
 	securityGroup := resourceName
 	vmReq.SecurityGroupIds = append(vmReq.SecurityGroupIds, securityGroup)
 	_, err = resource.GetResource(nsId, model.StrSecurityGroup, securityGroup)
@@ -1232,7 +1233,7 @@ func getVmReqFromDynamicReq(reqID string, nsId string, req *model.TbVmDynamicReq
 			log.Error().Err(err).Msg("Failed to get the securityGroup")
 			return &model.TbVmReq{}, err
 		}
-		common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Loading default securityGroup:" + resourceName, Time: time.Now()})
+		clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Loading default securityGroup:" + resourceName, Time: time.Now()})
 
 		// Check if the default security group exists
 		_, err := resource.GetResource(nsId, model.StrSecurityGroup, vmReq.ConnectionName)
@@ -1263,7 +1264,7 @@ func getVmReqFromDynamicReq(reqID string, nsId string, req *model.TbVmDynamicReq
 	vmReq.VmUserPassword = k.VmUserPassword
 
 	common.PrintJsonPretty(vmReq)
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Prepared resources for VM:" + vmReq.Name, Info: vmReq, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Prepared resources for VM:" + vmReq.Name, Info: vmReq, Time: time.Now()})
 
 	return vmReq, nil
 }
@@ -1516,15 +1517,15 @@ func CreateVm(wg *sync.WaitGroup, nsId string, mciId string, vmInfoData *model.T
 		url = model.SpiderRestUrl + "/regvm"
 	}
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -1935,7 +1936,7 @@ func getK8sClusterReqFromDynamicReq(reqID string, nsId string, dReq *model.TbK8s
 	// Default resource name has this pattern (nsId + "-shared-" + vmReq.ConnectionName)
 	resourceName := nsId + model.StrSharedResourceName + k8sReq.ConnectionName
 
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Setting vNet:" + resourceName, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Setting vNet:" + resourceName, Time: time.Now()})
 
 	k8sReq.VNetId = resourceName
 	_, err = resource.GetResource(nsId, model.StrVNet, k8sReq.VNetId)
@@ -1946,7 +1947,7 @@ func getK8sClusterReqFromDynamicReq(reqID string, nsId string, dReq *model.TbK8s
 			return emptyK8sReq, err
 		}
 
-		common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Loading default vNet:" + resourceName, Time: time.Now()})
+		clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Loading default vNet:" + resourceName, Time: time.Now()})
 
 		err2 := resource.CreateSharedResource(nsId, model.StrVNet, k8sReq.ConnectionName)
 		if err2 != nil {
@@ -1961,7 +1962,7 @@ func getK8sClusterReqFromDynamicReq(reqID string, nsId string, dReq *model.TbK8s
 	k8sReq.SubnetIds = append(k8sReq.SubnetIds, resourceName)
 	k8sReq.SubnetIds = append(k8sReq.SubnetIds, resourceName+"-01")
 
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Setting SSHKey:" + resourceName, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Setting SSHKey:" + resourceName, Time: time.Now()})
 
 	k8sngReq.SshKeyId = resourceName
 	_, err = resource.GetResource(nsId, model.StrSSHKey, k8sngReq.SshKeyId)
@@ -1972,7 +1973,7 @@ func getK8sClusterReqFromDynamicReq(reqID string, nsId string, dReq *model.TbK8s
 			return emptyK8sReq, err
 		}
 
-		common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Loading default SSHKey:" + resourceName, Time: time.Now()})
+		clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Loading default SSHKey:" + resourceName, Time: time.Now()})
 
 		err2 := resource.CreateSharedResource(nsId, model.StrSSHKey, k8sReq.ConnectionName)
 		if err2 != nil {
@@ -1985,7 +1986,7 @@ func getK8sClusterReqFromDynamicReq(reqID string, nsId string, dReq *model.TbK8s
 		log.Info().Msg("Found and utilize default SSHKey: " + k8sngReq.SshKeyId)
 	}
 
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Setting securityGroup:" + resourceName, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Setting securityGroup:" + resourceName, Time: time.Now()})
 
 	securityGroup := resourceName
 	k8sReq.SecurityGroupIds = append(k8sReq.SecurityGroupIds, securityGroup)
@@ -1997,7 +1998,7 @@ func getK8sClusterReqFromDynamicReq(reqID string, nsId string, dReq *model.TbK8s
 			return emptyK8sReq, err
 		}
 
-		common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Loading default securityGroup:" + resourceName, Time: time.Now()})
+		clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Loading default securityGroup:" + resourceName, Time: time.Now()})
 
 		err2 := resource.CreateSharedResource(nsId, model.StrSecurityGroup, k8sReq.ConnectionName)
 		if err2 != nil {
@@ -2046,7 +2047,7 @@ func getK8sClusterReqFromDynamicReq(reqID string, nsId string, dReq *model.TbK8s
 	k8sReq.Label = dReq.Label
 
 	common.PrintJsonPretty(k8sReq)
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Prepared resources for K8sCluster:" + k8sReq.Name, Info: k8sReq, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Prepared resources for K8sCluster:" + k8sReq.Name, Info: k8sReq, Time: time.Now()})
 
 	return k8sReq, nil
 }
@@ -2101,8 +2102,8 @@ func CreateK8sClusterDynamic(reqID string, nsId string, dReq *model.TbK8sCluster
 	*/
 
 	common.PrintJsonPretty(k8sReq)
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Prepared all resources for provisioning K8sCluster:" + k8sReq.Name, Info: k8sReq, Time: time.Now()})
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Start provisioning", Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Prepared all resources for provisioning K8sCluster:" + k8sReq.Name, Info: k8sReq, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Start provisioning", Time: time.Now()})
 
 	// Run create K8sCluster with the generated K8sCluster request (option != register)
 	option := "create"
@@ -2190,7 +2191,7 @@ func getK8sNodeGroupReqFromDynamicReq(reqID string, nsId string, k8sClusterInfo
 	k8sNgReq.Label = dReq.Label
 
 	common.PrintJsonPretty(k8sNgReq)
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Prepared resources for K8sNodeGroup:" + k8sNgReq.Name, Info: k8sNgReq, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Prepared resources for K8sNodeGroup:" + k8sNgReq.Name, Info: k8sNgReq, Time: time.Now()})
 
 	return k8sNgReq, nil
 }
@@ -2245,8 +2246,8 @@ func CreateK8sNodeGroupDynamic(reqID string, nsId string, k8sClusterId string, d
 	}
 
 	common.PrintJsonPretty(k8sNgReq)
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Prepared all resources for provisioning K8sNodeGroup:" + k8sNgReq.Name, Info: k8sNgReq, Time: time.Now()})
-	common.UpdateRequestProgress(reqID, common.ProgressInfo{Title: "Start provisioning", Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Prepared all resources for provisioning K8sNodeGroup:" + k8sNgReq.Name, Info: k8sNgReq, Time: time.Now()})
+	clientManager.UpdateRequestProgress(reqID, clientManager.ProgressInfo{Title: "Start provisioning", Time: time.Now()})
 
 	return resource.AddK8sNodeGroup(nsId, k8sClusterId, k8sNgReq)
 }
diff --git a/src/core/resource/common.go b/src/core/resource/common.go
index 95b02cc04..0be6a6381 100644
--- a/src/core/resource/common.go
+++ b/src/core/resource/common.go
@@ -27,6 +27,7 @@ import (
 	"time"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
@@ -349,15 +350,15 @@ func DelResource(nsId string, resourceType string, resourceId string, forceFlag
 	method := "DELETE"
 	//client.SetTimeout(60 * time.Second)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/customimage.go b/src/core/resource/customimage.go
index c8623c1b1..2d8030b4c 100644
--- a/src/core/resource/customimage.go
+++ b/src/core/resource/customimage.go
@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
 	validator "github.com/go-playground/validator/v10"
@@ -113,15 +114,15 @@ func LookupMyImage(connConfig string, myImageId string) (model.SpiderMyImageInfo
 	requestBody := model.SpiderConnectionName{}
 	requestBody.ConnectionName = connConfig
 
-	err := common.ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -220,15 +221,15 @@ func RegisterCustomImageWithId(nsId string, u *model.TbCustomImageReq) (model.Tb
 	}
 	callResult := model.SpiderMyImageInfo{}
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/image.go b/src/core/resource/image.go
index 6d123ea29..9f7f0e1f0 100644
--- a/src/core/resource/image.go
+++ b/src/core/resource/image.go
@@ -25,6 +25,7 @@ import (
 	"github.com/rs/zerolog/log"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
 
@@ -305,15 +306,15 @@ func LookupImageList(connConfigName string) (model.SpiderImageList, error) {
 	requestBody := model.SpiderConnectionName{}
 	requestBody.ConnectionName = connConfigName
 
-	err := common.ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.ShortDuration,
+		clientManager.ShortDuration,
 	)
 
 	if err != nil {
@@ -346,15 +347,15 @@ func LookupImage(connConfig string, imageId string) (model.SpiderImageInfo, erro
 	requestBody.ConnectionName = connConfig
 	callResult := model.SpiderImageInfo{}
 
-	err := common.ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/k8scluster.go b/src/core/resource/k8scluster.go
index 01b41e0d0..419f6ad81 100644
--- a/src/core/resource/k8scluster.go
+++ b/src/core/resource/k8scluster.go
@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
@@ -463,15 +464,15 @@ func CreateK8sCluster(nsId string, req *model.TbK8sClusterReq, option string) (*
 
 	var spClusterRes model.SpiderClusterRes
 
-	createErr = common.ExecuteHttpRequest(
+	createErr = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&spClusterRes,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if createErr != nil {
@@ -674,15 +675,15 @@ func AddK8sNodeGroup(nsId string, k8sClusterId string, u *model.TbK8sNodeGroupRe
 
 	var spClusterRes model.SpiderClusterRes
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&spClusterRes,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -743,15 +744,15 @@ func RemoveK8sNodeGroup(nsId, k8sClusterId, k8sNodeGroupName, option string) (bo
 	method := "DELETE"
 
 	var ifRes interface{}
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&ifRes,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -817,15 +818,15 @@ func SetK8sNodeGroupAutoscaling(nsId string, k8sClusterId string, k8sNodeGroupNa
 	method := "PUT"
 
 	var spSetAutoscalingRes model.SpiderSetAutoscalingRes
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&spSetAutoscalingRes,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -886,15 +887,15 @@ func ChangeK8sNodeGroupAutoscaleSize(nsId string, k8sClusterId string, k8sNodeGr
 	method := "PUT"
 
 	var spChangeAutoscaleSizeRes model.SpiderChangeAutoscaleSizeRes
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&spChangeAutoscaleSizeRes,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -951,15 +952,15 @@ func GetK8sCluster(nsId string, k8sClusterId string) (*model.TbK8sClusterInfo, e
 	}
 
 	var spClusterRes model.SpiderClusterRes
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&spClusterRes,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -1153,15 +1154,15 @@ func DeleteK8sCluster(nsId, k8sClusterId, option string) (bool, error) {
 	method := "DELETE"
 
 	var ifRes interface{}
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&ifRes,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	log.Debug().Msgf("option=%s", option)
@@ -1297,15 +1298,15 @@ func UpgradeK8sCluster(nsId string, k8sClusterId string, u *model.TbUpgradeK8sCl
 	method := "PUT"
 
 	var spClusterRes model.SpiderClusterRes
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&spClusterRes,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/objectStorage.go b/src/core/resource/objectStorage.go
index bc47eb80b..4d927feb8 100644
--- a/src/core/resource/objectStorage.go
+++ b/src/core/resource/objectStorage.go
@@ -20,6 +20,7 @@ import (
 	"os"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
@@ -229,15 +230,15 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 
 		resTrInfo := new(terrariumModel.TerrariumInfo)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqTr),
+			clientManager.SetUseBody(*reqTr),
 			reqTr,
 			resTrInfo,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -254,18 +255,18 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 		queryParams := "provider=" + objectStorageReq.CSP
 		url += "?" + queryParams
 
-		requestBody := common.NoBody
+		requestBody := clientManager.NoBody
 		resTerrariumEnv := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			resTerrariumEnv,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -292,15 +293,15 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -321,15 +322,15 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -349,15 +350,15 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 
 	// 	resInfracode := new(model.Response)
 
-	// 	err = common.ExecuteHttpRequest(
+	// 	err = clientManager.ExecuteHttpRequest(
 	// 		client,
 	// 		method,
 	// 		url,
 	// 		nil,
-	// 		common.SetUseBody(*reqInfracode),
+	// 		clientManager.SetUseBody(*reqInfracode),
 	// 		reqInfracode,
 	// 		resInfracode,
-	// 		common.VeryShortDuration,
+	// 		clientManager.VeryShortDuration,
 	// 	)
 
 	// 	if err != nil {
@@ -377,15 +378,15 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 
 	// 	resInfracode := new(model.Response)
 
-	// 	err = common.ExecuteHttpRequest(
+	// 	err = clientManager.ExecuteHttpRequest(
 	// 		client,
 	// 		method,
 	// 		url,
 	// 		nil,
-	// 		common.SetUseBody(*reqInfracode),
+	// 		clientManager.SetUseBody(*reqInfracode),
 	// 		reqInfracode,
 	// 		resInfracode,
-	// 		common.VeryShortDuration,
+	// 		clientManager.VeryShortDuration,
 	// 	)
 
 	// 	if err != nil {
@@ -406,18 +407,18 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 	// check the infracode (by `tofu plan`)
 	method := "POST"
 	url := fmt.Sprintf("%s/tr/%s/object-storage/plan", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resPlan := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resPlan,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -433,18 +434,18 @@ func CreateObjectStorage(nsId string, objectStorageReq *model.RestPostObjectStor
 	// and provide seperate api to check the status
 	method = "POST"
 	url = fmt.Sprintf("%s/tr/%s/object-storage", epTerrarium, trId)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resApply := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resApply,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -601,18 +602,18 @@ func GetObjectStorage(nsId string, objectStorageId string, detail string) (model
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -629,18 +630,18 @@ func GetObjectStorage(nsId string, objectStorageId string, detail string) (model
 	// Get resource info
 	method = "GET"
 	url = fmt.Sprintf("%s/tr/%s/%s?detail=%s", epTerrarium, trId, enrichments, detail)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resResourceInfo := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resResourceInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -775,18 +776,18 @@ func DeleteObjectStorage(nsId string, objectStorageId string) (model.SimpleMsg,
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -801,18 +802,18 @@ func DeleteObjectStorage(nsId string, objectStorageId string) (model.SimpleMsg,
 	// delete enrichments
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s/%s", epTerrarium, trId, enrichments)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteEnrichments := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteEnrichments,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -826,18 +827,18 @@ func DeleteObjectStorage(nsId string, objectStorageId string) (model.SimpleMsg,
 	// delete env
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s/%s/env", epTerrarium, trId, enrichments)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteEnv := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteEnv,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -851,18 +852,18 @@ func DeleteObjectStorage(nsId string, objectStorageId string) (model.SimpleMsg,
 	// delete terrarium
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteTr := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteTr,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -960,18 +961,18 @@ func GetRequestStatusOfObjectStorage(nsId string, objectStorageId string, reqId
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -986,18 +987,18 @@ func GetRequestStatusOfObjectStorage(nsId string, objectStorageId string, reqId
 	// Get resource info
 	method = "GET"
 	url = fmt.Sprintf("%s/tr/%s/%s/request/%s", epTerrarium, trId, enrichments, reqId)
-	reqReqStatus := common.NoBody
+	reqReqStatus := clientManager.NoBody
 	resReqStatus := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(reqReqStatus),
+		clientManager.SetUseBody(reqReqStatus),
 		&reqReqStatus,
 		resReqStatus,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/spec.go b/src/core/resource/spec.go
index 0e52ac9d9..419dd0e47 100644
--- a/src/core/resource/spec.go
+++ b/src/core/resource/spec.go
@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	validator "github.com/go-playground/validator/v10"
 	"github.com/go-resty/resty/v2"
@@ -85,15 +86,15 @@ func LookupSpecList(connConfig string) (model.SpiderSpecList, error) {
 	requestBody := model.SpiderConnectionName{}
 	requestBody.ConnectionName = connConfig
 
-	err := common.ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -130,15 +131,15 @@ func LookupSpec(connConfig string, specName string) (model.SpiderSpecInfo, error
 	requestBody.ConnectionName = connConfig
 	callResult := model.SpiderSpecInfo{}
 
-	err := common.ExecuteHttpRequest(
+	err := clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		&callResult,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/sqlDb.go b/src/core/resource/sqlDb.go
index 8911cd10b..c74964a9e 100644
--- a/src/core/resource/sqlDb.go
+++ b/src/core/resource/sqlDb.go
@@ -20,6 +20,7 @@ import (
 	"os"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
 	"github.com/cloud-barista/cb-tumblebug/src/kvstore/kvstore"
@@ -246,15 +247,15 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 
 		resTrInfo := new(terrariumModel.TerrariumInfo)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqTr),
+			clientManager.SetUseBody(*reqTr),
 			reqTr,
 			resTrInfo,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -271,18 +272,18 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 		queryParams := "provider=" + sqlDbReq.CSP
 		url += "?" + queryParams
 
-		requestBody := common.NoBody
+		requestBody := clientManager.NoBody
 		resTerrariumEnv := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			resTerrariumEnv,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -319,15 +320,15 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -352,15 +353,15 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -384,15 +385,15 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -415,15 +416,15 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -444,18 +445,18 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 	// check the infracode (by `tofu plan`)
 	method := "POST"
 	url := fmt.Sprintf("%s/tr/%s/sql-db/plan", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resPlan := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resPlan,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -471,18 +472,18 @@ func CreateSqlDB(nsId string, sqlDbReq *model.RestPostSqlDBRequest, retry string
 	// and provide seperate api to check the status
 	method = "POST"
 	url = fmt.Sprintf("%s/tr/%s/sql-db", epTerrarium, trId)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resApply := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resApply,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -639,18 +640,18 @@ func GetSqlDB(nsId string, sqlDbId string, detail string) (model.SqlDBInfo, erro
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -667,18 +668,18 @@ func GetSqlDB(nsId string, sqlDbId string, detail string) (model.SqlDBInfo, erro
 	// Get resource info
 	method = "GET"
 	url = fmt.Sprintf("%s/tr/%s/%s?detail=%s", epTerrarium, trId, enrichments, detail)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resResourceInfo := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resResourceInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -813,18 +814,18 @@ func DeleteSqlDB(nsId string, sqlDbId string) (model.SimpleMsg, error) {
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -839,18 +840,18 @@ func DeleteSqlDB(nsId string, sqlDbId string) (model.SimpleMsg, error) {
 	// delete enrichments
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s/%s", epTerrarium, trId, enrichments)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteEnrichments := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteEnrichments,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -864,18 +865,18 @@ func DeleteSqlDB(nsId string, sqlDbId string) (model.SimpleMsg, error) {
 	// delete env
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s/%s/env", epTerrarium, trId, enrichments)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteEnv := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteEnv,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -889,18 +890,18 @@ func DeleteSqlDB(nsId string, sqlDbId string) (model.SimpleMsg, error) {
 	// delete terrarium
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteTr := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteTr,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -998,18 +999,18 @@ func GetRequestStatusOfSqlDB(nsId string, sqlDbId string, reqId string) (model.R
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -1024,18 +1025,18 @@ func GetRequestStatusOfSqlDB(nsId string, sqlDbId string, reqId string) (model.R
 	// Get resource info
 	method = "GET"
 	url = fmt.Sprintf("%s/tr/%s/%s/request/%s", epTerrarium, trId, enrichments, reqId)
-	reqReqStatus := common.NoBody
+	reqReqStatus := clientManager.NoBody
 	resReqStatus := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(reqReqStatus),
+		clientManager.SetUseBody(reqReqStatus),
 		&reqReqStatus,
 		resReqStatus,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/subnet.go b/src/core/resource/subnet.go
index d6c73126d..1018bd328 100644
--- a/src/core/resource/subnet.go
+++ b/src/core/resource/subnet.go
@@ -21,6 +21,7 @@ import (
 	"strings"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/netutil"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
@@ -345,15 +346,15 @@ func CreateSubnet(nsId string, vNetId string, subnetReq *model.TbSubnetReq) (mod
 		}
 	}()
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -532,18 +533,18 @@ func GetSubnet(nsId string, vNetId string, subnetId string) (model.TbSubnetInfo,
 	queryParams := "?ConnectionName=" + subnetInfo.ConnectionName
 	url += queryParams
 
-	spReqt := common.NoBody
+	spReqt := clientManager.NoBody
 	var spResp spiderSubnetInfo
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -732,15 +733,15 @@ func DeleteSubnet(nsId string, vNetId string, subnetId string, actionParam strin
 	client := resty.New()
 	method := "DELETE"
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -900,18 +901,18 @@ func RefineSubnet(nsId string, vNetId string, subnetId string) (model.SimpleMsg,
 	queryParams := "?ConnectionName=" + subnetInfo.ConnectionName
 	url += queryParams
 
-	spReqt := common.NoBody
+	spReqt := clientManager.NoBody
 	var spResp spiderSubnetInfo
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	// if err != nil {
@@ -1124,15 +1125,15 @@ func RegisterSubnet(nsId string, vNetId string, subnetReq *model.TbRegisterSubne
 		}
 	}()
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -1334,15 +1335,15 @@ func DeregisterSubnet(nsId string, vNetId string, subnetId string) (model.Simple
 	client := resty.New()
 	method := "DELETE"
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/vnet.go b/src/core/resource/vnet.go
index bfdf38f3c..1485e8707 100644
--- a/src/core/resource/vnet.go
+++ b/src/core/resource/vnet.go
@@ -22,6 +22,7 @@ import (
 	"strings"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/netutil"
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
@@ -486,15 +487,15 @@ func CreateVNet(nsId string, vNetReq *model.TbVNetReq) (model.TbVNetInfo, error)
 		}
 	}()
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -693,7 +694,7 @@ func GetVNet(nsId string, vNetId string) (model.TbVNetInfo, error) {
 	// [Via Spider] Get a vNet and subnets
 	client := resty.New()
 	method := "GET"
-	spReqt := common.NoBody
+	spReqt := clientManager.NoBody
 	var spResp spiderVPCInfo
 
 	// API to create a vNet
@@ -701,15 +702,15 @@ func GetVNet(nsId string, vNetId string) (model.TbVNetInfo, error) {
 	queryParams := "?ConnectionName=" + vNetInfo.ConnectionName
 	url += queryParams
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -875,15 +876,15 @@ func DeleteVNet(nsId string, vNetId string, actionParam string) (model.SimpleMsg
 	client := resty.New()
 	method := "DELETE"
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -988,7 +989,7 @@ func RefineVNet(nsId string, vNetId string) (model.SimpleMsg, error) {
 	// [Via Spider] Get a vNet
 	client := resty.New()
 	method := "GET"
-	spReqt := common.NoBody
+	spReqt := clientManager.NoBody
 	var spResp spiderVPCInfo
 
 	// API to get a vNet
@@ -996,15 +997,15 @@ func RefineVNet(nsId string, vNetId string) (model.SimpleMsg, error) {
 	queryParams := "?ConnectionName=" + vNetInfo.ConnectionName
 	url += queryParams
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	// if err != nil {
@@ -1237,15 +1238,15 @@ func RegisterVNet(nsId string, vNetRegisterReq *model.TbRegisterVNetReq) (model.
 		}
 	}()
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
@@ -1503,15 +1504,15 @@ func DeregisterVNet(nsId string, vNetId string, withSubnets string) (model.Simpl
 	client := resty.New()
 	method := "DELETE"
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(spReqt),
+		clientManager.SetUseBody(spReqt),
 		&spReqt,
 		&spResp,
-		common.MediumDuration,
+		clientManager.MediumDuration,
 	)
 
 	if err != nil {
diff --git a/src/core/resource/vpn.go b/src/core/resource/vpn.go
index 231e5b6b0..6e5c2a7dc 100644
--- a/src/core/resource/vpn.go
+++ b/src/core/resource/vpn.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/common"
+	clientManager "github.com/cloud-barista/cb-tumblebug/src/core/common/client"
 	"github.com/cloud-barista/cb-tumblebug/src/core/common/label"
 
 	"github.com/cloud-barista/cb-tumblebug/src/core/model"
@@ -301,15 +302,15 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 
 			resTrInfo := new(terrariumModel.TerrariumInfo)
 
-			err = common.ExecuteHttpRequest(
+			err = clientManager.ExecuteHttpRequest(
 				client,
 				method,
 				url,
 				nil,
-				common.SetUseBody(*reqTr),
+				clientManager.SetUseBody(*reqTr),
 				reqTr,
 				resTrInfo,
-				common.VeryShortDuration,
+				clientManager.VeryShortDuration,
 			)
 
 			if err != nil {
@@ -323,18 +324,18 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 			// init env
 			method = "POST"
 			url = fmt.Sprintf("%s/tr/%s/vpn/gcp-aws/env", epTerrarium, trId)
-			requestBody := common.NoBody
+			requestBody := clientManager.NoBody
 			resTerrariumEnv := new(model.Response)
 
-			err = common.ExecuteHttpRequest(
+			err = clientManager.ExecuteHttpRequest(
 				client,
 				method,
 				url,
 				nil,
-				common.SetUseBody(requestBody),
+				clientManager.SetUseBody(requestBody),
 				&requestBody,
 				resTerrariumEnv,
-				common.VeryShortDuration,
+				clientManager.VeryShortDuration,
 			)
 
 			if err != nil {
@@ -371,15 +372,15 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -392,18 +393,18 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 		// check the infracode by plan
 		method = "POST"
 		url = fmt.Sprintf("%s/tr/%s/vpn/gcp-aws/plan", epTerrarium, trId)
-		requestBody := common.NoBody
+		requestBody := clientManager.NoBody
 		resPlan := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			resPlan,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -419,18 +420,18 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 		// and provide seperate api to check the status
 		method = "POST"
 		url = fmt.Sprintf("%s/tr/%s/vpn/gcp-aws", epTerrarium, trId)
-		requestBody = common.NoBody
+		requestBody = clientManager.NoBody
 		resApply := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			resApply,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -487,15 +488,15 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 
 			resTrInfo := new(terrariumModel.TerrariumInfo)
 
-			err = common.ExecuteHttpRequest(
+			err = clientManager.ExecuteHttpRequest(
 				client,
 				method,
 				url,
 				nil,
-				common.SetUseBody(*reqTr),
+				clientManager.SetUseBody(*reqTr),
 				reqTr,
 				resTrInfo,
-				common.VeryShortDuration,
+				clientManager.VeryShortDuration,
 			)
 
 			if err != nil {
@@ -509,18 +510,18 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 			// init env
 			method = "POST"
 			url = fmt.Sprintf("%s/tr/%s/vpn/gcp-azure/env", epTerrarium, trId)
-			requestBody := common.NoBody
+			requestBody := clientManager.NoBody
 			resTerrariumEnv := new(model.Response)
 
-			err = common.ExecuteHttpRequest(
+			err = clientManager.ExecuteHttpRequest(
 				client,
 				method,
 				url,
 				nil,
-				common.SetUseBody(requestBody),
+				clientManager.SetUseBody(requestBody),
 				&requestBody,
 				resTerrariumEnv,
-				common.VeryShortDuration,
+				clientManager.VeryShortDuration,
 			)
 
 			if err != nil {
@@ -559,15 +560,15 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 
 		resInfracode := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(*reqInfracode),
+			clientManager.SetUseBody(*reqInfracode),
 			reqInfracode,
 			resInfracode,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -581,18 +582,18 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 		// check the infracode by plan
 		method = "POST"
 		url = fmt.Sprintf("%s/tr/%s/vpn/gcp-azure/plan", epTerrarium, trId)
-		requestBody := common.NoBody
+		requestBody := clientManager.NoBody
 		resPlan := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			resPlan,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -609,18 +610,18 @@ func CreateSiteToSiteVPN(nsId string, mciId string, vpnReq *model.RestPostVpnReq
 		// and provide seperate api to check the status
 		method = "POST"
 		url = fmt.Sprintf("%s/tr/%s/vpn/gcp-azure", epTerrarium, trId)
-		requestBody = common.NoBody
+		requestBody = clientManager.NoBody
 		resApply := new(model.Response)
 
-		err = common.ExecuteHttpRequest(
+		err = clientManager.ExecuteHttpRequest(
 			client,
 			method,
 			url,
 			nil,
-			common.SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			resApply,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err != nil {
@@ -736,7 +737,7 @@ func retrieveEnrichmentsInfoInTerrarium(ctx context.Context, trId string, enrich
 	// Set Terrarium endpoint
 	epTerrarium := model.TerrariumRestUrl
 
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resRetrieving := new(model.Response)
 
 	// Set the start time and the expected end time
@@ -747,15 +748,15 @@ func retrieveEnrichmentsInfoInTerrarium(ctx context.Context, trId string, enrich
 	currentWaitDuration := maxWaitDuration
 
 	for {
-		err := common.ExecuteHttpRequest(
+		err := clientManager.ExecuteHttpRequest(
 			client,
 			"GET",
 			fmt.Sprintf("%s/tr/%s/%s?detail=refined", epTerrarium, trId, enrichments),
 			nil,
-			common.SetUseBody(requestBody),
+			clientManager.SetUseBody(requestBody),
 			&requestBody,
 			resRetrieving,
-			common.VeryShortDuration,
+			clientManager.VeryShortDuration,
 		)
 
 		if err == nil {
@@ -868,18 +869,18 @@ func GetSiteToSiteVPN(nsId string, mciId string, vpnId string, detail string) (m
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -896,18 +897,18 @@ func GetSiteToSiteVPN(nsId string, mciId string, vpnId string, detail string) (m
 	// Get resource info
 	method = "GET"
 	url = fmt.Sprintf("%s/tr/%s/%s?detail=%s", epTerrarium, trId, enrichments, detail)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resResourceInfo := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resResourceInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -1073,18 +1074,18 @@ func DeleteSiteToSiteVPN(nsId string, mciId string, vpnId string) (model.SimpleM
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -1099,18 +1100,18 @@ func DeleteSiteToSiteVPN(nsId string, mciId string, vpnId string) (model.SimpleM
 	// delete enrichments
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s/%s", epTerrarium, trId, enrichments)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteEnrichments := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteEnrichments,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -1124,18 +1125,18 @@ func DeleteSiteToSiteVPN(nsId string, mciId string, vpnId string) (model.SimpleM
 	// delete env
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s/%s/env", epTerrarium, trId, enrichments)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteEnv := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteEnv,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -1149,18 +1150,18 @@ func DeleteSiteToSiteVPN(nsId string, mciId string, vpnId string) (model.SimpleM
 	// delete terrarium
 	method = "DELETE"
 	url = fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody = common.NoBody
+	requestBody = clientManager.NoBody
 	resDeleteTr := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resDeleteTr,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -1263,18 +1264,18 @@ func GetRequestStatusOfSiteToSiteVpn(nsId string, mciId string, vpnId string, re
 	// Get the terrarium info
 	method := "GET"
 	url := fmt.Sprintf("%s/tr/%s", epTerrarium, trId)
-	requestBody := common.NoBody
+	requestBody := clientManager.NoBody
 	resTrInfo := new(terrariumModel.TerrariumInfo)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(requestBody),
+		clientManager.SetUseBody(requestBody),
 		&requestBody,
 		resTrInfo,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {
@@ -1289,18 +1290,18 @@ func GetRequestStatusOfSiteToSiteVpn(nsId string, mciId string, vpnId string, re
 	// Get resource info
 	method = "GET"
 	url = fmt.Sprintf("%s/tr/%s/%s/request/%s", epTerrarium, trId, enrichments, reqId)
-	reqReqStatus := common.NoBody
+	reqReqStatus := clientManager.NoBody
 	resReqStatus := new(model.Response)
 
-	err = common.ExecuteHttpRequest(
+	err = clientManager.ExecuteHttpRequest(
 		client,
 		method,
 		url,
 		nil,
-		common.SetUseBody(reqReqStatus),
+		clientManager.SetUseBody(reqReqStatus),
 		&reqReqStatus,
 		resReqStatus,
-		common.VeryShortDuration,
+		clientManager.VeryShortDuration,
 	)
 
 	if err != nil {