diff --git a/src/spaceone/core/connector/space_connector.py b/src/spaceone/core/connector/space_connector.py
index 7555f47..15c141a 100644
--- a/src/spaceone/core/connector/space_connector.py
+++ b/src/spaceone/core/connector/space_connector.py
@@ -44,6 +44,7 @@ def client(self) -> GRPCClient:
         return self._client
 
     def dispatch(self, method: str, params: dict = None, **kwargs) -> Any:
+        _LOGGER.debug(f"space_connector.dispatch : method: {method}")
         return self._call_api(method, params, **kwargs)
 
     def _call_api(
@@ -55,15 +56,23 @@ def _call_api(
         x_workspace_id: str = None,
     ) -> Any:
         resource, verb = self._parse_method(method)
+        _LOGGER.debug(f"space_connector.dispatch :: resource: {resource}, verb: {verb}")
+
         self._check_method(resource, verb)
 
         params = params or {}
+        _LOGGER.debug(f"space_connector.dispatch :: params: {params}")
         metadata = self._get_connection_metadata(token, x_domain_id, x_workspace_id)
+        _LOGGER.debug(f"space_connector.dispatch :: metadata: {metadata}")
 
         response_or_iterator = getattr(getattr(self._client, resource), verb)(
             params, metadata=metadata
         )
 
+        _LOGGER.debug(
+            f"space_connector.dispatch :: response_or_iterator: {response_or_iterator}"
+        )
+
         if self._return_type == "dict":
             if isinstance(response_or_iterator, types.GeneratorType):
                 return self._generate_response(response_or_iterator)
diff --git a/src/spaceone/core/pygrpc/client.py b/src/spaceone/core/pygrpc/client.py
index 898503d..d7374e7 100644
--- a/src/spaceone/core/pygrpc/client.py
+++ b/src/spaceone/core/pygrpc/client.py
@@ -2,7 +2,7 @@
 import types
 import grpc
 from google.protobuf.json_format import ParseDict
-from google.protobuf.message_factory import MessageFactory #, GetMessageClass
+from google.protobuf.message_factory import MessageFactory  # , GetMessageClass
 from google.protobuf.descriptor_pool import DescriptorPool
 from google.protobuf.descriptor import ServiceDescriptor, MethodDescriptor
 from grpc_reflection.v1alpha.proto_reflection_descriptor_database import (
@@ -109,16 +109,24 @@ def _retry_call(
     ):
         retries = 0
 
+        _LOGGER.debug(
+            f"client._retry_call.init :: client_call_details: {client_call_details}"
+        )
+
         while True:
             try:
+                _LOGGER.debug(f"client._retry_call.start!!!")
                 response_or_iterator = continuation(
                     client_call_details, request_or_iterator
                 )
+                _LOGGER.debug(f"client._retry_call.response_or_iterator Success!!!")
 
                 if is_stream:
                     response_or_iterator = self._generate_response(response_or_iterator)
                 else:
+                    _LOGGER.debug(f"client._retry_call.start _check_error!!!")
                     self._check_error(response_or_iterator)
+                    _LOGGER.debug(f"client._retry_call.finished _check_error!!!")
 
                 return response_or_iterator
 
@@ -207,13 +215,17 @@ def _bind_grpc_method(
         request_desc = self._desc_pool.FindMessageTypeByName(
             method_desc.input_type.full_name
         )
-        request_message_desc = MessageFactory(self._desc_pool).GetPrototype(request_desc)
+        request_message_desc = MessageFactory(self._desc_pool).GetPrototype(
+            request_desc
+        )
         # request_message_desc = GetMessageClass(request_desc)
 
         response_desc = self._desc_pool.FindMessageTypeByName(
             method_desc.output_type.full_name
         )
-        response_message_desc = MessageFactory(self._desc_pool).GetPrototype(response_desc)
+        response_message_desc = MessageFactory(self._desc_pool).GetPrototype(
+            response_desc
+        )
         # response_message_desc = GetMessageClass(response_desc)
 
         if method_desc.client_streaming and method_desc.server_streaming:
@@ -286,7 +298,9 @@ def _init_grpc_reflection(self):
                 request_desc = self._desc_pool.FindMessageTypeByName(
                     method_desc.input_type.full_name
                 )
-                self._request_map[method_key] = MessageFactory(self._desc_pool).GetPrototype(request_desc)
+                self._request_map[method_key] = MessageFactory(
+                    self._desc_pool
+                ).GetPrototype(request_desc)
                 # self._request_map[method_key] = GetMessageClass(request_desc)
 
                 if service_desc.name not in self._api_resources:
@@ -324,6 +338,11 @@ def client(endpoint=None, ssl_enabled=False, max_message_length=None, **client_o
     if endpoint is None:
         raise Exception("Client's endpoint is undefined.")
 
+    _LOGGER.debug(f"pygrpc.client :: endpoint: {endpoint}")
+    _LOGGER.debug(
+        f"pygrpc.client :: _GRPC_CHANNEL: {_GRPC_CHANNEL}  /  is in? {endpoint in _GRPC_CHANNEL}"
+    )
+
     if endpoint not in _GRPC_CHANNEL:
         options = []