Refactor helper codes

Move helper thread to common module
Refactor the interface between helper thread and worker

Change-Id: I0b61a2ed1a428f67cfbe3cc1411ace39e245932d
Issue-ID: MULTICLOUD-554
Signed-off-by: Bin Yang <bin.yang@windriver.com>

14 files changed, 518 insertions, 689 deletions

diff --git a/lenovo/thinkcloud/registration/tests/test_registration.py b/lenovo/thinkcloud/registration/tests/test_registration.py
index c8c8e6b5..c9de46d9 100644
--- a/lenovo/thinkcloud/registration/tests/test_registration.py
+++ b/lenovo/thinkcloud/registration/tests/test_registration.py
@@ -294,7 +294,7 @@ class TestRegistration(test_base.TestRequest):
             "registry"), "{}", content_type="application/json",
             HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
 
-        self.assertEquals(status.HTTP_500_INTERNAL_SERVER_ERROR,
+        self.assertEquals(status.HTTP_204_NO_CONTENT,
                           response.status_code)
 
     @mock.patch.object(VimDriverUtils, 'get_session')
diff --git a/lenovo/thinkcloud/registration/tests/test_registration2.py b/lenovo/thinkcloud/registration/tests/test_registration2.py
index 7abd6073..f49b023f 100644
--- a/lenovo/thinkcloud/registration/tests/test_registration2.py
+++ b/lenovo/thinkcloud/registration/tests/test_registration2.py
@@ -92,12 +92,12 @@ class TestRegistration2(unittest.TestCase):
             }
         )
 
-        resp = self.view.register_helper._discover_flavors(
+        retcode, content = self.view.register_helper._discover_flavors(
             vimid="lenovo-hudson-dc_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO
         )
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 0)
 
     def test_discover_flavors_w_hpa_numa(self):
         restcall.req_to_aai = mock.Mock()
@@ -112,9 +112,9 @@ class TestRegistration2(unittest.TestCase):
             }
         ),
 
-        resp = self.view.register_helper._discover_flavors(
+        retcode, content = self.view.register_helper._discover_flavors(
             vimid="lenovo-hudson-dc_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO
         )
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 11)
diff --git a/newton/newton/registration/tests/test_registration.py b/newton/newton/registration/tests/test_registration.py
index cfc2cd59..5481822f 100644
--- a/newton/newton/registration/tests/test_registration.py
+++ b/newton/newton/registration/tests/test_registration.py
@@ -291,7 +291,7 @@ class TestRegistration(test_base.TestRequest):
             "registry"), "{}", content_type="application/json",
             HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
 
-        self.assertEquals(status.HTTP_500_INTERNAL_SERVER_ERROR,
+        self.assertEquals(status.HTTP_204_NO_CONTENT,
                           response.status_code)
 
     @mock.patch.object(VimDriverUtils, 'get_session')
diff --git a/newton/newton/registration/tests/test_registration.py.bak b/newton/newton/registration/tests/test_registration.py.bak
deleted file mode 100644
index d5be81de..00000000
--- a/newton/newton/registration/tests/test_registration.py.bak
+++ /dev/null
@@ -1,350 +0,0 @@
-# Copyright (c) 2017 Intel Corporation, Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import mock
-
-from django.conf import settings
-from rest_framework import status
-
-from common.utils import restcall
-from newton_base.openoapi.flavor import Flavors
-from newton_base.tests import mock_info
-from newton_base.tests import test_base
-from newton_base.util import VimDriverUtils
-
-MOCK_GET_TENANT_RESPONSE = {
-    "projects": [
-        {"id": "1", "name": "project"},
-        {"id": "2", "name": "project2"},
-    ]
-}
-
-MOCK_GET_FLAVOR_RESPONSE = {
-    "flavors": [
-        {
-            "id": "1", "name": "micro", "vcpus": 1, "ram": "1MB",
-            "disk": "1G", "OS-FLV-EXT-DATA:ephemeral": False,
-            "swap": True, "os-flavor-access:is_public": True,
-            "OS-FLV-DISABLED:disabled": True, "link": [{"href": 1}]
-        },
-        {
-            "id": "2", "name": "mini", "vcpus": 2, "ram": "2MB",
-            "disk": "2G", "OS-FLV-EXT-DATA:ephemeral": True,
-            "swap": False, "os-flavor-access:is_public": True,
-            "OS-FLV-DISABLED:disabled": True
-        },
-    ]
-}
-
-MOCK_GET_EXTRA_SPECS_RESPONSE = {
-    "extra_specs": {
-        "hw:cpu_sockets": 4,
-        "hw:cpu_cores": 4,
-        "hw:cpu_policy": "dedicated",
-        "hw:numa_nodes": 3,
-        "hw:numa_cpus.1": [0, 1],
-        "hw:numa_mem.1": 2,
-        "pci_passthrough:alias": "mycrypto-8086-0443:4",
-        "aggregate_instance_extra_spec:sriov-device-intel-1832-9475": "true",
-        "hw:mem_page_size": "1GB"
-    }
-}
-
-MOCK_HPA_RESPONSE = """{
-    "basicCapabilities": {
-        "info": {
-            "hpa-feature": "basicCapabilities",
-            "hpa-version": "v1",
-            "architecture": "generic"
-        },
-        "hpa-attributes": {
-            "vcpus": {
-                "key": "numVirtualCpu",
-                "unit": null
-            },
-            "ram": {
-                "key": "virtualMemSize",
-                "unit": "GB"
-            }
-        }
-    },
-    "localStorage": {
-        "info": {
-            "hpa-feature": "localStorage",
-            "hpa-version": "v1",
-            "architecture": "generic"
-        },
-        "hpa-attributes": {
-            "disk": {
-                "key": "diskSize",
-                "unit": "GB"
-            },
-            "swap": {
-                "key": "swapMemSize",
-                "unit": "MB"
-            }
-        }
-    },
-    "cpuTopology": {
-        "info": {
-            "hpa-feature": "cpuTopology",
-            "hpa-version": "v1",
-            "architecture": "generic"
-        },
-        "hpa-attributes": {
-            "hw:cpu_sockets": {
-                "key": "numCpuSockets",
-                "unit": null
-            },
-            "hw:cpu_cores": {
-                "key": "numCpuCores",
-                "unit": null
-            },
-            "hw:cpu_threads": {
-                "key": "numCpuThreads",
-                "unit": null
-            }
-        }
-    },
-    "cpuPinning": {
-        "info": {
-            "hpa-feature": "cpuPinning",
-            "hpa-version": "v1",
-            "architecture": "generic"
-        },
-        "hpa-attributes": {
-            "hw:cpu_thread_policy": {
-                "key": "logicalCpuThreadPinningPolicy",
-                "unit": null
-            },
-            "hw:cpu_policy": {
-                "key": "logicalCpuPinningPolicy",
-                "unit": null
-            }
-        }
-    },
-    "numa": {
-        "info": {
-            "hpa-feature": "numa",
-            "hpa-version": "v1",
-            "architecture": "generic"
-        },
-        "hpa-attributes": {
-            "hw:numa_nodes": {
-                "key": "numaNodes",
-                "unit": null
-            },
-            "hw:numa_cpus": {
-                "key": "numaCpu",
-                "unit": null
-            },
-            "hw:numa_mem": {
-                "key": "numaMem",
-                "unit": "GB"
-            }
-        }
-    },
-    "hugePages": {
-        "info": {
-            "hpa-feature": "hugePages",
-            "hpa-version": "v1",
-            "architecture": "generic"
-        },
-        "hpa-attributes": {
-            "hw:mem_page_size": {
-                "key": "memoryPageSize",
-                "unit": null
-            }
-        }
-    },
-    "pciePassthrough": {
-        "info": {
-            "hpa-feature": "pciePassthrough",
-            "hpa-version": "v1",
-            "architecture": "generic"
-        },
-        "hpa-attributes": {
-            "pci_count": {
-                "key": "pciCount",
-                "unit": null
-            },
-            "pci_vendor_id": {
-                "key": "pciVendorId",
-                "unit": null
-            },
-            "pci_device_id": {
-                "key": "pciDeviceId",
-                "unit": null
-            }
-        }
-    }
-}"""
-
-MOCK_GET_IMAGE_RESPONSE = {
-    "images": [
-        {
-            "id": "1", "name": "cirros", "self": "test",
-            "os_distro": "CirrOS", "os_version": "0.3",
-            "application": "test", "application_vendor": "ONAP",
-            "application_version": 1, "architecture": "x86",
-            "schema": None
-        },
-        {
-            "id": "2", "name": "cirros", "self": "test",
-            "os_distro": "CirrOS", "os_version": "0.3",
-            "application": "test", "application_vendor": "ONAP",
-            "application_version": 1, "architecture": "x86",
-            "schema": "req_resource"
-        },
-    ]
-}
-
-MOCK_GET_AZ_RESPONSE = {
-    "availabilityZoneInfo": [
-        {
-            "zoneName": "production",
-            "zoneState": {"available": True},
-            "hosts": {"hypervisor": "kvm"}
-        },
-        {
-            "zoneName": "testing",
-        },
-    ]
-}
-
-MOCK_HYPERVISOR_RESPONSE = {
-    "hypervisors": [
-        {"hypervisor_type": "kvm"}
-    ]
-}
-
-MOCK_GET_SNAPSHOT_RESPONSE = {
-    "snapshots": [
-        {
-            "id": 1, "name": "test", "metadata":
-            {
-                "architecture": "x86", "os-distro": "clearlinux",
-                "os-version": "276", "vendor": "intel", "version": 3,
-                "selflink": "test", "prev-snapshot-id": "test-id"
-            }
-        },
-        {"id": 2, "name": "test2"}
-    ]
-}
-
-MOCK_GET_HYPERVISOR_RESPONSE = {
-    "hypervisors": [
-        {
-            "hypervisor_hostname": "testing", "state": "ACTIVE",
-            "id": 1, "local_gb": 256, "memory_mb": 1024,
-            "hypervisor_links": "link", "host_ip": "127.0.0.1",
-            "cpu_info":
-                u'{"topology": {"cores": 8, "threads": 16,'
-                u'"sockets": 4}}'
-        },
-        {
-            "hypervisor_hostname": "testing2", "state": "XXX",
-            "id": 1, "local_gb": 256, "memory_mb": 1024,
-            "hypervisor_links": "link", "host_ip": "127.0.0.1",
-        }
-    ]
-}
-
-TEST_REGISTER_ENDPOINT_REQUEST = {
-    "defaultTenant": "project1"
-}
-
-
-class TestFlavors(test_base.TestRequest):
-    def setUp(self):
-        super(TestFlavors, self).setUp()
-        self.req_to_aai_backup = restcall.req_to_aai
-
-    def tearDown(self):
-        super(TestFlavors, self).tearDown()
-        restcall.req_to_aai = self.req_to_aai_backup
-
-    def _get_mock_response(self, return_value=None):
-        mock_response = mock.Mock(spec=test_base.MockResponse)
-        mock_response.status_code = status.HTTP_200_OK
-        mock_response.json.return_value = return_value
-        return mock_response
-
-    @mock.patch.object(Flavors, '_get_flavor_extra_specs')
-    @mock.patch.object(VimDriverUtils, 'get_session')
-    @mock.patch.object(VimDriverUtils, 'get_vim_info')
-    def test_register_endpoint_successfully(
-            self, mock_get_vim_info, mock_get_session,
-            mock_get_extra_specs):
-        settings.AAI_SCHEMA_VERSION = "v13"
-        restcall.req_to_aai = mock.Mock()
-        restcall.req_to_aai.return_value = (0, {}, status.HTTP_200_OK)
-        mock_get_vim_info.return_value = mock_info.MOCK_VIM_INFO
-        mock_get_session.return_value = test_base.get_mock_session(
-            ["get"], {
-                "side_effect": [
-                    self._get_mock_response(MOCK_GET_TENANT_RESPONSE),
-                    self._get_mock_response(MOCK_GET_FLAVOR_RESPONSE),
-                    self._get_mock_response(MOCK_GET_IMAGE_RESPONSE),
-                    self._get_mock_response(),
-                    self._get_mock_response(MOCK_GET_AZ_RESPONSE),
-                    self._get_mock_response(MOCK_HYPERVISOR_RESPONSE),
-                    self._get_mock_response(
-                        MOCK_GET_SNAPSHOT_RESPONSE),
-                    self._get_mock_response(
-                        MOCK_GET_HYPERVISOR_RESPONSE)
-                ]
-            })
-        mock_extra_specs_response = mock.Mock(spec=test_base.MockResponse)
-        mock_extra_specs_response.status_code = status.HTTP_200_OK
-        mock_extra_specs_response.json.return_value = MOCK_GET_EXTRA_SPECS_RESPONSE
-        mock_get_extra_specs.return_value = mock_extra_specs_response
-
-        with mock.patch('__builtin__.open', mock.mock_open(read_data=MOCK_HPA_RESPONSE)) as mock_file:
-            response = self.client.post((
-                "/api/%s/v0/windriver-hudson-dc_RegionOne/"
-                "registry" % test_base.MULTIVIM_VERSION),
-                TEST_REGISTER_ENDPOINT_REQUEST,
-                HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
-
-            self.assertEquals(status.HTTP_202_ACCEPTED,
-                              response.status_code)
-
-    @mock.patch.object(VimDriverUtils, 'delete_vim_info')
-    def test_unregister_endpoint_successfully(
-            self, mock_delete_vim_info):
-        mock_delete_vim_info.return_value = 0
-
-        response = self.client.delete((
-            "/api/%s/v0/windriver-hudson-dc_RegionOne/"
-            "registry" % test_base.MULTIVIM_VERSION),
-            "{}", content_type="application/json",
-            HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
-
-        self.assertEquals(status.HTTP_202_ACCEPTED,
-                          response.status_code)
-
-    @mock.patch.object(VimDriverUtils, 'delete_vim_info')
-    def test_fail_unregister_endpoint(
-            self, mock_delete_vim_info):
-        mock_delete_vim_info.return_value = 1
-
-        response = self.client.delete((
-            "/api/%s/v0/windriver-hudson-dc_RegionOne/"
-            "registry" % test_base.MULTIVIM_VERSION),
-            "{}", content_type="application/json",
-            HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
-
-        self.assertEquals(status.HTTP_500_INTERNAL_SERVER_ERROR,
-                          response.status_code)
diff --git a/ocata/ocata/registration/tests/test_registration.py b/ocata/ocata/registration/tests/test_registration.py
index 2daca137..540f170b 100644
--- a/ocata/ocata/registration/tests/test_registration.py
+++ b/ocata/ocata/registration/tests/test_registration.py
@@ -294,7 +294,7 @@ class TestRegistration(test_base.TestRequest):
             "registry"), "{}", content_type="application/json",
             HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
 
-        self.assertEquals(status.HTTP_500_INTERNAL_SERVER_ERROR,
+        self.assertEquals(status.HTTP_204_NO_CONTENT,
                           response.status_code)
 
     @mock.patch.object(VimDriverUtils, 'get_session')
diff --git a/ocata/ocata/registration/tests/test_registration2.py b/ocata/ocata/registration/tests/test_registration2.py
index bfb7d7a5..13851763 100644
--- a/ocata/ocata/registration/tests/test_registration2.py
+++ b/ocata/ocata/registration/tests/test_registration2.py
@@ -92,12 +92,12 @@ class TestRegistration2(unittest.TestCase):
             }
         )
 
-        resp = self.view.register_helper._discover_flavors(
+        retcode, content = self.view.register_helper._discover_flavors(
             vimid="windriver-hudson-dc_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO
         )
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 0)
 
     def test_discover_flavors_w_hpa_numa(self):
         restcall.req_to_aai = mock.Mock()
@@ -112,9 +112,9 @@ class TestRegistration2(unittest.TestCase):
             }
         ),
 
-        resp = self.view.register_helper._discover_flavors(
+        retcode, content = self.view.register_helper._discover_flavors(
             vimid="windriver-hudson-dc_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO
         )
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 11)
diff --git a/pike/pike/registration/tests/test_registration.py b/pike/pike/registration/tests/test_registration.py
index becbbcc1..84840cdb 100644
--- a/pike/pike/registration/tests/test_registration.py
+++ b/pike/pike/registration/tests/test_registration.py
@@ -294,7 +294,7 @@ class TestRegistration(test_base.TestRequest):
             "registry"), "{}", content_type="application/json",
             HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
 
-        self.assertEquals(status.HTTP_500_INTERNAL_SERVER_ERROR,
+        self.assertEquals(status.HTTP_204_NO_CONTENT,
                           response.status_code)
 
     @mock.patch.object(VimDriverUtils, 'get_session')
diff --git a/share/common/msapi/helper.py b/share/common/msapi/helper.py
index 3e10c0fd..979c7feb 100644
--- a/share/common/msapi/helper.py
+++ b/share/common/msapi/helper.py
@@ -11,9 +11,14 @@
 
 import json
 import logging
-import re
+# import re
+import uuid
 
-from common.exceptions import VimDriverNewtonException
+import threading
+import datetime
+import time
+
+# from common.exceptions import VimDriverNewtonException
 from common.utils import restcall
 
 from rest_framework import status
@@ -21,6 +26,7 @@ from rest_framework import status
 logger = logging.getLogger(__name__)
 
 
+# Helper of MultiCloud API invocation
 class Helper(object):
 
     @staticmethod
@@ -53,4 +59,220 @@ class Helper(object):
                     content = json.JSONDecoder().decode(ret[1])
                     ret[1] = content
                 return ret
-        return [1, None, status.HTTP_404_NOT_FOUND] # return resource not found in case no type found
\ No newline at end of file
+        return [1, None, status.HTTP_404_NOT_FOUND] # return resource not found in case no type found
+
+
+# Helper of AAI resource access
+class MultiCloudAAIHelper(object):
+
+    def __init__(self, multicloud_prefix, aai_base_url):
+        self.proxy_prefix = multicloud_prefix
+        self.aai_base_url = aai_base_url
+        self._logger = logger
+        # super(MultiCloudAAIHelper, self).__init__()
+
+    def _get_list_resources(
+            self, resource_url, service_type, session, viminfo,
+            vimid, content_key):
+        service = {
+            'service_type': service_type,
+            'interface': 'public'
+        }
+
+        # identity service should not filtered by region since it is might be first call
+        # to figure out available region list
+        if service_type != 'identity':
+            service['region_name'] = viminfo['openstack_region_id']\
+                if viminfo.get('openstack_region_id') else viminfo['cloud_region_id']
+
+        self._logger.debug("making request with URI:%s,%s" % (resource_url, service))
+        resp = session.get(resource_url, endpoint_filter=service)
+        self._logger.debug("request returns with status %s" % resp.status_code)
+        if resp.status_code == status.HTTP_200_OK:
+            self._logger.debug("with content:%s" % resp.json())
+            content = resp.json()
+            return content.get(content_key)
+        return  None # failed to discover resources
+
+    def _update_resoure(self, cloud_owner, cloud_region_id,
+                        resoure_id, resource_info, resource_type):
+        if cloud_owner and cloud_region_id:
+            self._logger.debug(
+                ("_update_resoure,vimid:%(cloud_owner)s"
+                 "_%(cloud_region_id)s req_to_aai: %(resoure_id)s, "
+                 "%(resource_type)s, %(resource_info)s")
+                % {
+                    "cloud_owner": cloud_owner,
+                    "cloud_region_id": cloud_region_id,
+                    "resoure_id": resoure_id,
+                    "resource_type": resource_type,
+                    "resource_info": resource_info,
+                })
+
+            # get the resource first
+            resource_url = ("/cloud-infrastructure/cloud-regions/"
+                     "cloud-region/%(cloud_owner)s/%(cloud_region_id)s/"
+                     "%(resource_type)ss/%(resource_type)s/%(resoure_id)s"
+                     % {
+                         "cloud_owner": cloud_owner,
+                         "cloud_region_id": cloud_region_id,
+                         "resoure_id": resoure_id,
+                         "resource_type": resource_type,
+                     })
+
+            # get cloud-region
+            retcode, content, status_code = \
+                restcall.req_to_aai(resource_url, "GET")
+
+            # add resource-version
+            if retcode == 0 and content:
+                content = json.JSONDecoder().decode(content)
+                #resource_info["resource-version"] = content["resource-version"]
+                content.update(resource_info)
+                resource_info = content
+
+            #then update the resource
+            retcode, content, status_code = \
+                restcall.req_to_aai(resource_url, "PUT", content=resource_info)
+
+            self._logger.debug(
+                ("_update_resoure,vimid:%(cloud_owner)s"
+                 "_%(cloud_region_id)s req_to_aai: %(resoure_id)s, "
+                 "return %(retcode)s, %(content)s, %(status_code)s")
+                % {
+                    "cloud_owner": cloud_owner,
+                    "cloud_region_id": cloud_region_id,
+                    "resoure_id": resoure_id,
+                    "retcode": retcode,
+                    "content": content,
+                    "status_code": status_code,
+                })
+            return retcode, content
+        # unknown cloud owner,region_id
+        return (
+            11,
+            "Unknown Cloud Region ID: %s ,%s" %(cloud_owner, cloud_region_id)
+        )
+    pass
+
+
+# thread helper
+class MultiCloudThreadHelper(object):
+    '''
+    thread to register infrastructure resource into AAI
+    '''
+
+    @staticmethod
+    def get_epoch_now_usecond():
+        '''
+        get epoch timestamp of this moment in usecond
+        :return:
+        '''
+        now_time = datetime.datetime.now()
+        epoch_time_sec = time.mktime(now_time.timetuple())
+        return int(epoch_time_sec * 1e6 + now_time.microsecond)
+
+    def __init__(self):
+        # format of a backlog item:
+        # {
+        #   "id": unique string to identify this item in backlog,
+        #   "worker": pointer to helper method
+        #   "payload": opaque object to pass to the worker for processing
+        #   "repeat": interval in micro-seconds for repeating this worker, 0 for one time worker
+        #   "timestamp": time stamp of last invocation of this worker, 0 for initial state
+        # }
+        # format of backlog:
+        # {"<id value of backlog item>": <backlog item>, ...}
+        self.backlog = {}
+        # expired backlog items
+        self.expired_backlog = {}
+        # self.lock = threading.Lock()
+        self.state_ = 0  # 0: stopped, 1: started
+        self.thread = None
+
+    def state(self):
+        return self.state_
+
+    def start(self):
+        if 0 == self.state_:
+            self.state_ = 1
+            self.thread = MultiCloudThreadHelper.HelperThread(self)
+            self.thread.start()
+        else:
+            pass
+
+    def stop(self):
+        self.state_ = 0
+
+    def add(self, backlog_item):
+        if not hasattr(backlog_item, "worker"):
+            return None
+        if not hasattr(backlog_item, "id"):
+            backlog_item["id"] = str(uuid.uuid1())
+        if not hasattr(backlog_item, "repeat"):
+            backlog_item["repeat"] = 0
+        backlog_item["timestamp"] = 0
+
+        # self.lock.acquire()
+        self.backlog.update(backlog_item["id"], backlog_item)
+        # self.lock.release()
+        return len(self.backlog)
+
+    def get(self, backlog_id):
+        self.backlog.get(backlog_id, None) or self.expired_backlog.get(backlog_id, None)
+
+    def remove(self, backlog_id):
+        # self.lock.acquire()
+        self.backlog.pop(backlog_id, None)
+        self.expired_backlog.pop(backlog_id, None)
+        # self.lock.release()
+
+    def reset(self):
+        # self.lock.acquire()
+        self.backlog.clear()
+        self.expired_backlog.clear()
+        # self.lock.release()
+
+    def count(self):
+        return len(self.backlog)
+
+    class HelperThread(threading.Thread):
+        def __init__(self, owner):
+            threading.Thread.__init__(self)
+            self.daemon = True
+            self.duration = 0
+            self.owner = owner
+
+        def run(self):
+            logger.debug("Start processing backlogs")
+            while self.owner.state_ == 1 and self.owner.count() > 0:
+                for backlog_id, item in self.owner.backlog:
+                    # check interval for repeatable backlog item
+                    now = MultiCloudThreadHelper.get_epoch_now_usecond()
+                    repeat_interval = item.get("repeat", 0)
+                    if repeat_interval > 0:
+                        timestamp = item.get("timestamp", 0)
+                        # compare interval with elapsed time.
+                        # workaround the case of timestamp turnaround
+                        if repeat_interval > (now - timestamp
+                                              if now > timestamp
+                                              else repeat_interval):
+                            # not time to run this backlog item yet
+                            continue
+
+                    worker = item.get("worker", None)
+                    payload = item.get("payload", None)
+                    try:
+                        item["status"] = worker(payload) or 0
+                    except Exception as e:
+                        item["status"] = e.message
+                    item["timestamp"] = now
+                    if item.get("repeat", 0) == 0:
+                        self.owner.remove(backlog_id)
+                        self.owner.expired_backlog[backlog_id] = item
+                    pass
+                pass
+            # end of loop
+            logger.debug("stop processing backlogs")
+            self.owner.state_ = 0
+            # end of processing
diff --git a/share/newton_base/registration/registration.py b/share/newton_base/registration/registration.py
index c7636ef2..6e8f8809 100644
--- a/share/newton_base/registration/registration.py
+++ b/share/newton_base/registration/registration.py
@@ -16,7 +16,6 @@ import logging
 import json
 import uuid
 import traceback
-import threading
 
 from keystoneauth1.exceptions import HttpError
 from rest_framework import status
@@ -25,6 +24,7 @@ from rest_framework.views import APIView
 
 from common.exceptions import VimDriverNewtonException
 from common.msapi import extsys
+from common.msapi import helper
 from common.utils import restcall
 from newton_base.util import VimDriverUtils
 
@@ -37,6 +37,10 @@ class Registry(APIView):
         if not hasattr(self, "_logger"):
             self._logger = logger
 
+        if not hasattr(self, "register_thread"):
+            # dedicate thread to offload vim registration process
+            self.register_thread = helper.MultiCloudThreadHelper()
+
         if not hasattr(self, "register_helper") or not self.register_helper:
             if not hasattr(self, "proxy_prefix"):
                 self.proxy_prefix = "multicloud"
@@ -49,11 +53,17 @@ class Registry(APIView):
         self._logger.debug("with data: %s" % request.data)
 
         try:
-
-            thread1 = RegisterHelperThread(self.register_helper.registry)
-            thread1.addv0(vimid)
-            if 0 == thread1.state():
-                thread1.start()
+            # compose the one time backlog item
+            backlog_item = {
+                "id": vimid,
+                "worker": self.register_helper.registryV0,
+                "payload": (self.register_helper, vimid),
+                "repeat": 0,
+                "status": (1, "The registration process waits to be scheduled to run")
+            }
+            self.register_thread.add(backlog_item)
+            if 0 == self.register_thread.state():
+                self.register_thread.start()
 
             return Response(status=status.HTTP_202_ACCEPTED)
 
@@ -68,15 +78,47 @@ class Registry(APIView):
                 data={'error': str(e)},
                 status=status.HTTP_500_INTERNAL_SERVER_ERROR)
 
+    def get(self, request, vimid):
+        try:
+            backlog_item = self.register_thread.get(vimid)
+            if backlog_item:
+                return Response(
+                    data={'status': backlog_item.get("status", "Status not available, vimid: %s" % vimid)},
+                    status=status.HTTP_200_OK)
+            else:
+                return Response(
+                    data={
+                        'error': "Registration process for "
+                                 "Cloud Region not found: %s"
+                                 % vimid
+                    },
+                    status=status.HTTP_404_NOT_FOUND)
+        except Exception as e:
+            self._logger.error(traceback.format_exc())
+            return Response(
+                data={'error': str(e)},
+                status=status.HTTP_500_INTERNAL_SERVER_ERROR)
+
     def delete(self, request, vimid=""):
         self._logger.debug("Registration--delete::data> %s" % request.data)
         self._logger.debug("Registration--delete::vimid > %s"% vimid)
         try:
 
-            retcode = RegistryHelper.unregistry(vimid)
+            # compose the one time backlog item
+            backlog_item = {
+                "id": vimid,
+                "worker": self.register_helper.unregistryV0,
+                "payload": (self.register_helper, vimid),
+                "repeat": 0,
+                "status": (1, "The registration process waits to be scheduled to run")
+            }
+            self.register_thread.add(backlog_item)
+            if 0 == self.register_thread.state():
+                self.register_thread.start()
 
-            #ret_code = VimDriverUtils.delete_vim_info(vimid)
-            return Response(status=status.HTTP_204_NO_CONTENT if retcode==0 else status.HTTP_500_INTERNAL_SERVER_ERROR)
+            return Response(
+                status=status.HTTP_204_NO_CONTENT
+            )
         except VimDriverNewtonException as e:
             return Response(data={'error': e.content}, status=e.status_code)
         except HttpError as e:
@@ -88,7 +130,8 @@ class Registry(APIView):
                             status=status.HTTP_500_INTERNAL_SERVER_ERROR)
 
 
-class RegistryHelper(object):
+
+class RegistryHelper(helper.MultiCloudAAIHelper):
     '''
     Helper code to discover and register a cloud region's resource
     '''
@@ -97,8 +140,15 @@ class RegistryHelper(object):
         self.proxy_prefix = multicloud_prefix
         self.aai_base_url = aai_base_url
         self._logger = logger
+        super(RegistryHelper, self).__init__(multicloud_prefix, aai_base_url)
 
-    def registry(self, vimid=""):
+    def registryV1(self, cloud_owner, cloud_region_id):
+        # cloud_owner = payload.get("cloud-owner", None)
+        # cloud_region_id = payload.get("cloud-region-id", None)
+        vimid = extsys.encode_vim_id(cloud_owner, cloud_region_id)
+        return self.registryV0(vimid)
+
+    def registryV0(self, vimid):
         # populate proxy identity url
         self._update_proxy_identity_endpoint(vimid)
 
@@ -106,48 +156,85 @@ class RegistryHelper(object):
         # get token:
         viminfo = VimDriverUtils.get_vim_info(vimid)
         if not viminfo:
-            raise VimDriverNewtonException(
-                "There is no cloud-region with {cloud-owner}_{cloud-region-id}=%s in AAI" % vimid)
+            return (
+                10,
+                "Cloud Region not found in AAI: %s" % vimid
+            )
 
         # set the default tenant since there is no tenant info in the VIM yet
         sess = VimDriverUtils.get_session(
             viminfo, tenant_name=viminfo['tenant'])
 
         # step 1. discover all projects and populate into AAI
-        self._discover_tenants(vimid, sess, viminfo)
+        retcode, status = self._discover_tenants(vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return (
+        #         retcode, status
+        #     )
 
         # discover all flavors
-        self._discover_flavors(vimid, sess, viminfo)
+        retcode, status = self._discover_flavors(vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return (
+        #         retcode, status
+        #     )
 
         # discover all images
-        self._discover_images(vimid, sess, viminfo)
+        retcode, status = self._discover_images(vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return (
+        #         retcode, status
+        #     )
 
         # discover all az
-        self._discover_availability_zones(vimid, sess, viminfo)
+        retcode, status = self._discover_availability_zones(vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return (
+        #         retcode, status
+        #     )
 
         # discover all vg
         #self._discover_volumegroups(vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return (
+        #         retcode, status
+        #     )
 
         # discover all snapshots
         #self._discover_snapshots(vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return retcode, status
 
         # discover all server groups
         #self.discover_servergroups(request, vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return retcode, status
 
         # discover all pservers
         #self._discover_pservers(vimid, sess, viminfo)
+        # if 0 != retcode:
+        #     return retcode, status
 
-        return 0
-
+        return (
+            0,
+            "Registration finished for Cloud Region: %s" % vimid
+        )
 
-    def unregistry(self, vimid=""):
+    def unregistryV1(self, cloud_owner, cloud_region_id):
+        # cloud_owner = payload.get("cloud-owner", None)
+        # cloud_region_id = payload.get("cloud-region-id", None)
+        vimid = extsys.encode_vim_id(cloud_owner, cloud_region_id)
+        return self.unregistryV0(vimid)
 
+    def unregistryV0(self, vimid):
         # prepare request resource to vim instance
         # get token:
         viminfo = VimDriverUtils.get_vim_info(vimid)
         if not viminfo:
-            raise VimDriverNewtonException(
-                "There is no cloud-region with {cloud-owner}_{cloud-region-id}=%s in AAI" % vimid)
+            return (
+                10,
+                "Cloud Region not found:" % vimid
+            )
 
         cloud_owner, cloud_region_id = extsys.decode_vim_id(vimid)
 
@@ -164,8 +251,14 @@ class RegistryHelper(object):
             restcall.req_to_aai(resource_url, "GET")
 
         # add resource-version
+        cloudregiondata = {}
         if retcode == 0 and content:
             cloudregiondata = json.JSONDecoder().decode(content)
+        else:
+            return (
+                10,
+                "Cloud Region not found: %s, %s" % (cloud_owner, cloud_region_id)
+            )
 
         # step 1. remove all tenants
         tenants = cloudregiondata.get("tenants", None)
@@ -314,87 +407,7 @@ class RegistryHelper(object):
         retcode, content, status_code = \
             restcall.req_to_aai(resource_url, "DELETE")
 
-        return retcode, content, status_code
-
-
-    def _get_list_resources(
-            self, resource_url, service_type, session, viminfo,
-            vimid, content_key):
-        service = {
-            'service_type': service_type,
-            'interface': 'public'
-        }
-
-        # identity service should not filtered by region since it is might be first call
-        # to figure out available region list
-        if service_type != 'identity':
-            service['region_name'] = viminfo['openstack_region_id']\
-                if viminfo.get('openstack_region_id') else viminfo['cloud_region_id']
-
-        self._logger.info("making request with URI:%s,%s" % (resource_url,service))
-        resp = session.get(resource_url, endpoint_filter=service)
-        self._logger.info("request returns with status %s" % resp.status_code)
-        if resp.status_code == status.HTTP_200_OK:
-            self._logger.debug("with content:%s" % resp.json())
-            content = resp.json()
-            return content.get(content_key)
-        return  # failed to discover resources
-
-    def _update_resoure(self, cloud_owner, cloud_region_id,
-                        resoure_id, resource_info, resource_type):
-        if cloud_owner and cloud_region_id:
-            self._logger.debug(
-                ("_update_resoure,vimid:%(cloud_owner)s"
-                 "_%(cloud_region_id)s req_to_aai: %(resoure_id)s, "
-                 "%(resource_type)s, %(resource_info)s")
-                % {
-                    "cloud_owner": cloud_owner,
-                    "cloud_region_id": cloud_region_id,
-                    "resoure_id": resoure_id,
-                    "resource_type": resource_type,
-                    "resource_info": resource_info,
-                })
-
-            #get the resource first
-            resource_url = ("/cloud-infrastructure/cloud-regions/"
-                     "cloud-region/%(cloud_owner)s/%(cloud_region_id)s/"
-                     "%(resource_type)ss/%(resource_type)s/%(resoure_id)s"
-                     % {
-                         "cloud_owner": cloud_owner,
-                         "cloud_region_id": cloud_region_id,
-                         "resoure_id": resoure_id,
-                         "resource_type": resource_type,
-                     })
-
-            # get cloud-region
-            retcode, content, status_code = \
-                restcall.req_to_aai(resource_url, "GET")
-
-            # add resource-version
-            if retcode == 0 and content:
-                content = json.JSONDecoder().decode(content)
-                #resource_info["resource-version"] = content["resource-version"]
-                content.update(resource_info)
-                resource_info = content
-
-            #then update the resource
-            retcode, content, status_code = \
-                restcall.req_to_aai(resource_url, "PUT", content=resource_info)
-
-            self._logger.debug(
-                ("_update_resoure,vimid:%(cloud_owner)s"
-                 "_%(cloud_region_id)s req_to_aai: %(resoure_id)s, "
-                 "return %(retcode)s, %(content)s, %(status_code)s")
-                % {
-                    "cloud_owner": cloud_owner,
-                    "cloud_region_id": cloud_region_id,
-                    "resoure_id": resoure_id,
-                    "retcode": retcode,
-                    "content": content,
-                    "status_code": status_code,
-                })
-            return retcode
-        return 1  # unknown cloud owner,region_id
+        return retcode, content
 
     def _discover_tenants(self, vimid="", session=None, viminfo=None):
         try:
@@ -410,10 +423,12 @@ class RegistryHelper(object):
                 self._update_resoure(
                     cloud_owner, cloud_region_id, tenant['id'],
                     tenant_info, "tenant")
-
+            return (0, "succeed")
         except VimDriverNewtonException as e:
             self._logger.error("VimDriverNewtonException: status:%s, response:%s" % (e.http_status, e.content))
-            return
+            return (
+                e.http_status, e.content
+            )
         except HttpError as e:
             if e.http_status == status.HTTP_403_FORBIDDEN:
                 ### get the tenant information from the token response
@@ -434,12 +449,21 @@ class RegistryHelper(object):
 
                 except Exception as ex:
                     self._logger.error(traceback.format_exc())
+                    return (
+                        11,
+                        ex.message
+                    )
             else:
                 self._logger.error("HttpError: status:%s, response:%s" % (e.http_status, e.response.json()))
-            return
+                return (
+                    e.http_status, e.response.json()
+                )
         except Exception as e:
             self._logger.error(traceback.format_exc())
-            return
+            return (
+                11,
+                e.message
+            )
 
     def _discover_flavors(self, vimid="", session=None, viminfo=None):
         try:
@@ -472,19 +496,26 @@ class RegistryHelper(object):
                     hpa_capabilities = self._get_hpa_capabilities(flavor, extraResp, viminfo)
                     flavor_info['hpa-capabilities'] = {'hpa-capability': hpa_capabilities}
 
-                self._update_resoure(
+                retcode, content = self._update_resoure(
                     cloud_owner, cloud_region_id, flavor['id'],
                     flavor_info, "flavor")
 
+            return (0, "succeed")
         except VimDriverNewtonException as e:
             self._logger.error("VimDriverNewtonException: status:%s, response:%s" % (e.http_status, e.content))
-            return
+            return (
+                e.http_status, e.content
+            )
         except HttpError as e:
             self._logger.error("HttpError: status:%s, response:%s" % (e.http_status, e.response.json()))
-            return
+            return (
+                e.http_status, e.response.json()
+            )
         except Exception as e:
             self._logger.error(traceback.format_exc())
-            return
+            return (
+                11, e.message
+            )
 
     def _get_hpa_capabilities(self, flavor, extra_specs, viminfo):
         hpa_caps = []
@@ -571,8 +602,11 @@ class RegistryHelper(object):
                                                    'hpa-attribute-value':
                                                        '{{\"value\":\"{0}\",\"unit\":\"{1}\"}}'.format(flavor['ram'],"MB")
                                                                })
-        except Exception:
+        except Exception as e:
             self._logger.error(traceback.format_exc())
+            return (
+                11, e.message
+            )
 
         return basic_capability
 
@@ -927,16 +961,22 @@ class RegistryHelper(object):
                         # parse the schema? TBD
                         # self.update_image(cloud_owner, cloud_region_id, image_info)
                         #metadata_info = {}
-
+            return (0, "succeed")
         except VimDriverNewtonException as e:
             self._logger.error("VimDriverNewtonException: status:%s, response:%s" % (e.http_status, e.content))
-            return
+            return (
+                e.http_status, e.content
+            )
         except HttpError as e:
             self._logger.error("HttpError: status:%s, response:%s" % (e.http_status, e.response.json()))
-            return
+            return (
+                e.http_status, e.response.json()
+            )
         except Exception as e:
             self._logger.error(traceback.format_exc())
-            return
+            return (
+                11, e.message
+            )
 
     def _discover_availability_zones(self, vimid="", session=None,
                                      viminfo=None):
@@ -968,37 +1008,18 @@ class RegistryHelper(object):
 
                 az_info['hypervisor-type'] = 'QEMU' # default for OpenStack
 
-                # if az.get('hosts'):
-                #    for (k, v) in az['hosts'].items():
-                #         req_resource = "/os-hypervisors/detail?hypervisor_hostname_pattern=%s" % k
-                #         service = {'service_type': "compute",
-                #                    'interface': 'public',
-                #                    'region_name': viminfo['openstack_region_id']
-                #                    if viminfo.get('openstack_region_id')
-                #                    else viminfo['cloud_region_id']
-                #                    }
-                #
-                #         self._logger.info("making request with URI:%s" % req_resource)
-                #         resp = session.get(req_resource, endpoint_filter=service)
-                #         self._logger.info("request returns with status %s" % resp.status_code)
-                #         if resp.status_code == status.HTTP_200_OK:
-                #             self._logger.debug("with content:%s" % resp.json())
-                #             pass
-                #         content = resp.json()
-                #         if resp.status_code != status.HTTP_200_OK and not content[0]:
-                #             continue
-                #         az_info['hypervisor-type'] = content['hypervisors'][0]['hypervisor_type']\
-                #             if len(content.get('hypervisors')) else ''
-                #
-                #         break
-                ret = self._update_resoure(
+                ret, content = self._update_resoure(
                     cloud_owner, cloud_region_id, az['zoneName'], az_info,
                     "availability-zone")
                 if ret != 0:
                     # failed to update image
                     self._logger.debug("failed to populate az info into AAI: %s, az name: %s, ret:%s"
                                        % (vimid, az_info['availability-zone-name'], ret))
-                    return None
+                    # return (
+                    #     ret,
+                    #     "fail to popluate az info into AAI:%s" % content
+                    # )
+                    continue
 
                 # populate pservers:
                 for hostname in pservers_info:
@@ -1023,17 +1044,22 @@ class RegistryHelper(object):
                     self._update_pserver_relation_az(cloud_owner, cloud_region_id, pinfo, azName)
                     self._update_pserver_relation_cloudregion(cloud_owner, cloud_region_id, pinfo)
 
-                return az_pserver_info
-
+            return (0, az_pserver_info)
         except VimDriverNewtonException as e:
             self._logger.error("VimDriverNewtonException: status:%s, response:%s" % (e.http_status, e.content))
-            return None
+            return (
+                e.http_status, e.content
+            )
         except HttpError as e:
             self._logger.error("HttpError: status:%s, response:%s" % (e.http_status, e.response.json()))
-            return None
+            return (
+                e.http_status, e.response.json()
+            )
         except Exception as e:
             self._logger.error(traceback.format_exc())
-            return None
+            return (
+                11, e.message
+            )
 
     # def _discover_volumegroups(self, vimid="", session=None, viminfo=None):
     #     cloud_owner, cloud_region_id = extsys.decode_vim_id(vimid)
@@ -1076,23 +1102,33 @@ class RegistryHelper(object):
                     snapshot_info['snapshot-selflink'] = ss['metadata'].get('selflink')
                     snapshot_info['prev-snapshot-id'] = ss['metadata'].get('prev-snapshot-id')
 
-                ret = self._update_resoure(
+                ret, content = self._update_resoure(
                     cloud_owner, cloud_region_id, ss['id'], snapshot_info,
                     "snapshot")
                 if ret != 0:
                     # failed to update image
                     self._logger.debug("failed to populate snapshot info into AAI: %s, snapshot-id: %s, ret:%s"
                                        % (vimid, snapshot_info['snapshot-id'], ret))
-
+                    return (
+                        ret,
+                        "fail to populate snapshot into AAI:%s" % content
+                    )
+            return 0, "Succeed"
         except VimDriverNewtonException as e:
             self._logger.error("VimDriverNewtonException: status:%s, response:%s" % (e.http_status, e.content))
-            return
+            return (
+                e.http_status, e.content
+            )
         except HttpError as e:
             self._logger.error("HttpError: status:%s, response:%s" % (e.http_status, e.response.json()))
-            return
+            return (
+                e.http_status, e.response.json()
+            )
         except Exception as e:
             self._logger.error(traceback.format_exc())
-            return
+            return (
+                11, e.message
+            )
 
     # def _discover_servergroups(self, vimid="", session=None, viminfo=None):
     #     for sg in self._get_list_resources(
@@ -1151,9 +1187,17 @@ class RegistryHelper(object):
                               cloud_owner, cloud_region_id,
                               pserverinfo['hostname'], retcode, content,
                               status_code))
-
-
-    def _update_pserver_relation_cloudregion(self, cloud_owner, cloud_region_id, pserverinfo):
+        return (
+            0,
+            "succeed"
+        )
+
+    def _update_pserver_relation_cloudregion(
+            self,
+            cloud_owner,
+            cloud_region_id,
+            pserverinfo
+    ):
         related_link = ("%s/cloud-infrastructure/cloud-regions/"
                         "cloud-region/%s/%s"% (
                             self.aai_base_url, cloud_owner,
@@ -1194,6 +1238,10 @@ class RegistryHelper(object):
                            % (cloud_owner, cloud_region_id, cloud_owner, cloud_region_id,
                               pserverinfo['hostname'], retcode, content,
                               status_code))
+        return (
+            0,
+            "succeed"
+        )
 
     def _update_pserver(self, cloud_owner, cloud_region_id, pserverinfo):
         '''
@@ -1254,8 +1302,13 @@ class RegistryHelper(object):
             self._logger.debug("update_snapshot,vimid:%s_%s req_to_aai: %s, return %s, %s, %s"
                                % (cloud_owner,cloud_region_id, pserverinfo['hostname'], retcode, content, status_code))
 
-            return retcode
-        return 1  # unknown cloud owner,region_id
+            return retcode, content
+        else:
+            # unknown cloud owner,region_id
+            return (
+                10,
+                "Cloud Region not found: %s,%s" % (cloud_owner, cloud_region_id)
+            )
 
     def _discover_pservers(self, vimid="", session=None, viminfo=None):
         try:
@@ -1287,22 +1340,30 @@ class RegistryHelper(object):
                         n_cpus = cputopo['cores'] * cputopo['threads'] * cputopo['sockets']
                         hypervisor_info['number-of-cpus'] = n_cpus
 
-                ret = self._update_pserver(cloud_owner, cloud_region_id,
+                ret, content = self._update_pserver(cloud_owner, cloud_region_id,
                                           hypervisor_info)
                 if ret != 0:
                     # failed to update image
                     self._logger.debug("failed to populate pserver info into AAI: %s, hostname: %s, ret:%s"
                                        % (vimid, hypervisor_info['hostname'], ret))
+                    return ret, "fail to update pserver to AAI:%s" % content
 
+            return 0, "succeed"
         except VimDriverNewtonException as e:
             self._logger.error("VimDriverNewtonException: status:%s, response:%s" % (e.http_status, e.content))
-            return
+            return (
+                e.http_status, e.content
+            )
         except HttpError as e:
             self._logger.error("HttpError: status:%s, response:%s" % (e.http_status, e.response.json()))
-            return
+            return (
+                e.http_status, e.response.json()
+            )
         except Exception as e:
             self._logger.error(traceback.format_exc())
-            return
+            return (
+                11, e.message
+            )
 
     def _update_proxy_identity_endpoint(self, vimid):
         '''
@@ -1335,96 +1396,30 @@ class RegistryHelper(object):
 
                     self._logger.debug("update_proxy_identity_endpoint,vimid:%s req_to_aai: %s, return %s, %s, %s"
                                        % (vimid, viminfo['identity-url'], retcode, content, status_code))
+                    return 0, "succeed"
                 else:
                     self._logger.debug("failure: update_proxy_identity_endpoint,vimid:%s req_to_aai: return %s, %s, %s"
                                        % (vimid, retcode, content, status_code))
+                    return retcode, content
+            else:
+                return (
+                    10,
+                    "Cloud Region not found: %s" % vimid
+                )
 
         except VimDriverNewtonException as e:
             self._logger.error("VimDriverNewtonException: status:%s, response:%s" % (e.http_status, e.content))
-            return
+            return (
+                e.http_status, e.content
+            )
         except HttpError as e:
             self._logger.error("HttpError: status:%s, response:%s" % (e.http_status, e.response.json()))
-            return
+            return (
+                e.http_status, e.response.json()
+            )
         except Exception as e:
             self._logger.error(traceback.format_exc())
-            return
-
-
-class RegisterHelperThread(threading.Thread):
-    '''
-    thread to register infrastructure resource into AAI
-    '''
-
-    def __init__(self, registry_helper):
-        threading.Thread.__init__(self)
-        self.daemon = True
-        self.duration = 0
-        self.helper = registry_helper
-
-        # The queue of IDs of cloud regions, format:
-        # v0: "owner1_regionid1"
-        self.queuev0 = []
-
-        # v1: {"cloud-owner": "owner1", "cloud-region-id": "regionid1"},
-        self.queuev1 = []
-        self.lock = threading.Lock()
-
-        self.state_ = 0  # 0: stopped, 1: started
-
-    def addv0(self, vimid):
-        self.lock.acquire()
-        self.queuev0.append(vimid)
-        self.lock.release()
-        return len(self.queuev0)
-
-    def removev0(self, vimid):
-        '''
-        remove cloud region from list
-        '''
-        self.queuev0 = [x for x in self.queuev0 if x != vimid]
-
-    def resetv0(self):
-        self.queuev0 = []
-
-    def countv0(self):
-        return len(self.queuev0)
-
-    def addv1(self, cloud_owner, cloud_region_id):
-        self.lock.acquire()
-        self.queuev1.append({"cloud-owner": cloud_owner, "cloud-region-id": cloud_region_id})
-        self.lock.release()
-        return len(self.queuev1)
-
-    def removev1(self, cloud_owner, cloud_region_id):
-        '''
-        remove cloud region from list
-        '''
-        self.queuev1 = [x for x in self.queuev1 if x["cloud-owner"] != cloud_owner or x["cloud-region-id"] != cloud_region_id]
-
-    def resetv1(self):
-        self.queuev1 = []
-
-    def countv1(self):
-        return len(self.queuev1)
-
-    def state(self):
-        return self.state_
-
-    def run(self):
-        logger.debug("Starting registration thread")
-        self.state_ = 1
-        while self.helper and len(self.queuev0) > 0 and len(self.queuev1) > 0:
-            self.lock.acquire()
-            vimidv1 = self.queuev1.pop()
-            self.lock.release()
-            vimid = extsys.encode_vim_id(vimidv1["cloud-owner"], vimidv1["cloud-region-id"])
-            self.helper(vimid)
-
-            self.lock.acquire()
-            vimidv0 = self.queuev0.pop()
-            self.lock.release()
-            self.helper(vimidv0)
-
-        self.state_ = 0
-        # end of processing
+            return (
+                11, e.message
+            )
 
diff --git a/share/starlingx_base/registration/registration.py b/share/starlingx_base/registration/registration.py
index 59074568..fa79e5b3 100644
--- a/share/starlingx_base/registration/registration.py
+++ b/share/starlingx_base/registration/registration.py
@@ -25,12 +25,17 @@ from newton_base.registration import registration as newton_registration
 from rest_framework import status
 from rest_framework.response import Response
 from common.msapi import extsys
+from common.msapi import helper
 from keystoneauth1.exceptions import HttpError
 from newton_base.util import VimDriverUtils
 from common.utils import restcall
 from django.core.cache import cache
 
 logger = logging.getLogger(__name__)
+
+# global var: Audition thread
+gAZCapAuditThread = helper.MultiCloudThreadHelper()
+
 # DEBUG=True
 
 # APIv0 handler upgrading: leverage APIv1 handler
@@ -44,14 +49,24 @@ class APIv0Registry(newton_registration.Registry):
         self._logger.info("registration with :  %s" % vimid)
 
         # vim registration will trigger the start the audit of AZ capacity
-        gAZCapAuditThread.addv0(vimid)
+        worker_self = InfraResourceAuditor(
+            settings.MULTICLOUD_API_V1_PREFIX,
+            settings.AAI_BASE_URL
+        )
+        backlog_item = {
+        "id": vimid,
+        "worker": worker_self.azcap_audit,
+        "payload": (worker_self, vimid),
+        "repeat": 5*1000000, # repeat every 5 seconds
+        }
+        gAZCapAuditThread.add(backlog_item)
         if 0 == gAZCapAuditThread.state():
             gAZCapAuditThread.start()
         return super(APIv0Registry, self).post(request, vimid)
 
     def delete(self, request, vimid=""):
         self._logger.debug("unregister cloud region: %s" % vimid)
-        gAZCapAuditThread.removev0(vimid)
+        gAZCapAuditThread.remove(vimid)
         return super(APIv0Registry, self).delete(request, vimid)
 
 
@@ -62,8 +77,8 @@ class Registry(APIv0Registry):
 
 class APIv1Registry(newton_registration.Registry):
     def __init__(self):
-        super(APIv1Registry, self).__init__()
         self.register_helper = RegistryHelper(settings.MULTICLOUD_API_V1_PREFIX, settings.AAI_BASE_URL)
+        super(APIv1Registry, self).__init__()
         # self._logger = logger
 
     def post(self, request, cloud_owner="", cloud_region_id=""):
@@ -74,7 +89,17 @@ class APIv1Registry(newton_registration.Registry):
             vimid = extsys.encode_vim_id(cloud_owner, cloud_region_id)
 
             # vim registration will trigger the start the audit of AZ capacity
-            gAZCapAuditThread.addv0(vimid)
+            worker_self = InfraResourceAuditor(
+                settings.MULTICLOUD_API_V1_PREFIX,
+                settings.AAI_BASE_URL
+            )
+            backlog_item = {
+                "id": vimid,
+                "worker": worker_self.azcap_audit,
+                "payload": (worker_self, vimid),
+                "repeat": 5 * 1000000,  # repeat every 5 seconds
+            }
+            gAZCapAuditThread.add(backlog_item)
             if 0 == gAZCapAuditThread.state():
                 gAZCapAuditThread.start()
 
@@ -95,7 +120,7 @@ class APIv1Registry(newton_registration.Registry):
                            % (cloud_owner, cloud_region_id))
 
         vimid = extsys.encode_vim_id(cloud_owner, cloud_region_id)
-        gAZCapAuditThread.removev0(vimid)
+        gAZCapAuditThread.remove(vimid)
         return super(APIv1Registry, self).delete(request, vimid)
 
 
@@ -107,7 +132,7 @@ class RegistryHelper(newton_registration.RegistryHelper):
         super(RegistryHelper, self).__init__(multicloud_prefix, aai_base_url)
         # self._logger = logger
 
-    def registry(self, vimid=""):
+    def registryV0(self, vimid=""):
         '''
         extend base method
         '''
@@ -132,7 +157,7 @@ class RegistryHelper(newton_registration.RegistryHelper):
             viminfo, tenant_name=viminfo['tenant'])
 
         # discover the regions, expect it always returns a list (even empty list)
-        # cloud_owner, cloud_region_id = extsys.decode_vim_id(vimid)
+        cloud_owner, cloud_region_id = extsys.decode_vim_id(vimid)
         # region_ids = self._discover_regions(cloud_owner, cloud_region_id, sess, viminfo)
         region_ids = self._discover_regions(vimid, sess, viminfo)
 
@@ -298,8 +323,7 @@ class RegistryHelper(newton_registration.RegistryHelper):
         return 1  # unknown cloud owner,region_id
 
     # def _discover_regions(self, cloud_owner="", cloud_region_id="",
-    def _discover_regions(self, vimid="",
-                          session=None, viminfo=None):
+    def _discover_regions(self, vimid, session=None, viminfo=None):
         try:
             regions = []
             # vimid = extsys.encode_vim_id(cloud_owner, cloud_region_id)
@@ -343,7 +367,7 @@ class InfraResourceAuditor(newton_registration.RegistryHelper):
         self._logger = logger
         # super(InfraResourceAuditor, self).__init__();
 
-    def azcap_audit(self, vimid=""):
+    def azcap_audit(self, vimid):
         viminfo = VimDriverUtils.get_vim_info(vimid)
         if not viminfo:
             self._logger.warn("azcap_audit no valid vimid: %s" % vimid)
@@ -398,8 +422,6 @@ class InfraResourceAuditor(newton_registration.RegistryHelper):
 
                 # get list of host names
                 pservers_info = [k for (k, v) in az['hosts'].items()]
-                # set the association between az and pservers
-                #az_pserver_info[azName] = az['hosts']
 
                 # Get current cap info of azName
                 azCapCacheKey = "cap_" + vimid + "_" + azName
@@ -463,63 +485,3 @@ class InfraResourceAuditor(newton_registration.RegistryHelper):
         except Exception as e:
             self._logger.error("azcap_audit raise exception: %s" % e)
             pass
-
-
-class AuditorHelperThread(threading.Thread):
-    '''
-    thread to register infrastructure resource into AAI
-    '''
-
-    def __init__(self, audit_helper):
-        threading.Thread.__init__(self)
-        self.daemon = True
-        self.duration = 0
-        self.helper = audit_helper
-
-        # The set of IDs of cloud regions, format:
-        # v0: "owner1_regionid1"
-        self.queuev0 = set()
-        self.lock = threading.Lock()
-        self.state_ = 0  # 0: stopped, 1: started
-
-    def addv0(self, vimid=""):
-        self.lock.acquire()
-        self.queuev0.add(vimid)
-        self.lock.release()
-        return len(self.queuev0)
-
-    def removev0(self, vimid):
-        '''
-        discard cloud region from list without raise any exception
-        '''
-        self.queuev0.discard(vimid)
-
-    def resetv0(self):
-        self.queuev0.clear()
-
-    def countv0(self):
-        return len(self.queuev0)
-
-    def state(self):
-        return self.state_
-
-    def run(self):
-        logger.debug("Start the Audition thread")
-        self.state_ = 1
-        while self.helper and self.countv0() > 0:
-            for vimidv0 in self.queuev0:
-                self.helper(vimidv0)
-            # sleep for a while in seconds
-            time.sleep(5)
-
-        self.state_ = 0
-        logger.debug("Stop the Audition thread")
-        # end of processing
-
-# global Audition thread
-gAZCapAuditThread = AuditorHelperThread(
-    InfraResourceAuditor(
-        settings.MULTICLOUD_API_V1_PREFIX,
-        settings.AAI_BASE_URL).azcap_audit
-)
-
diff --git a/starlingx/starlingx/registration/tests/test_registration.py b/starlingx/starlingx/registration/tests/test_registration.py
index 99f5ffc5..d4af22b6 100644
--- a/starlingx/starlingx/registration/tests/test_registration.py
+++ b/starlingx/starlingx/registration/tests/test_registration.py
@@ -271,7 +271,7 @@ class TestRegistration(test_base.TestRequest):
             "registry"), "{}", content_type="application/json",
             HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
 
-        self.assertEquals(status.HTTP_500_INTERNAL_SERVER_ERROR,
+        self.assertEquals(status.HTTP_204_NO_CONTENT,
                           response.status_code)
 
     @mock.patch.object(VimDriverUtils, 'get_session')
diff --git a/starlingx/starlingx/registration/tests/test_registration2.py b/starlingx/starlingx/registration/tests/test_registration2.py
index 6f470eea..d2084ecf 100644
--- a/starlingx/starlingx/registration/tests/test_registration2.py
+++ b/starlingx/starlingx/registration/tests/test_registration2.py
@@ -86,12 +86,12 @@ class TestRegistration2(unittest.TestCase):
             ["get"], {"get": {
                 "content": MOCK_GET_FLAVOR_RESPONSE}}),
 
-        resp = self.view.register_helper._discover_flavors(
+        retcode, content = self.view.register_helper._discover_flavors(
             vimid="starlingx_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO
         )
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 11)
 
     def test_discover_flavors_w_hpa_numa(self):
         restcall.req_to_aai = mock.Mock()
@@ -103,9 +103,9 @@ class TestRegistration2(unittest.TestCase):
                     "content": MOCK_GET_FLAVOR_EXTRASPECS_RESPONSE_w_hpa_numa}
             ]}),
 
-        resp = self.view.register_helper._discover_flavors(
+        retcode, content = self.view.register_helper._discover_flavors(
             vimid="starlingx_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO
         )
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 11)
diff --git a/windriver/titanium_cloud/registration/tests/test_registration.py b/windriver/titanium_cloud/registration/tests/test_registration.py
index 749fba62..49df5b23 100644
--- a/windriver/titanium_cloud/registration/tests/test_registration.py
+++ b/windriver/titanium_cloud/registration/tests/test_registration.py
@@ -271,7 +271,7 @@ class TestRegistration(test_base.TestRequest):
             "registry"), "{}", content_type="application/json",
             HTTP_X_AUTH_TOKEN=mock_info.MOCK_TOKEN_ID)
 
-        self.assertEquals(status.HTTP_500_INTERNAL_SERVER_ERROR,
+        self.assertEquals(status.HTTP_204_NO_CONTENT,
                           response.status_code)
 
     @mock.patch.object(VimDriverUtils, 'get_session')
diff --git a/windriver/titanium_cloud/registration/tests/test_registration2.py b/windriver/titanium_cloud/registration/tests/test_registration2.py
index 495b2126..e00c6adc 100644
--- a/windriver/titanium_cloud/registration/tests/test_registration2.py
+++ b/windriver/titanium_cloud/registration/tests/test_registration2.py
@@ -87,10 +87,10 @@ class TestRegistration2(unittest.TestCase):
             ["get"], {"get": {
                 "content": MOCK_GET_FLAVOR_RESPONSE}}),
 
-        resp = self.view.register_helper._discover_flavors(vimid="windriver-hudson-dc_RegionOne",
+        retcode, content = self.view.register_helper._discover_flavors(vimid="windriver-hudson-dc_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO)
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 11)
 
     def test_discover_flavors_w_hpa_numa(self):
         restcall.req_to_aai = mock.Mock()
@@ -102,7 +102,7 @@ class TestRegistration2(unittest.TestCase):
                     "content": MOCK_GET_FLAVOR_EXTRASPECS_RESPONSE_w_hpa_numa}
             ]}),
 
-        resp = self.view.register_helper._discover_flavors(vimid="windriver-hudson-dc_RegionOne",
+        retcode, content = self.view.register_helper._discover_flavors(vimid="windriver-hudson-dc_RegionOne",
             session=mock_session, viminfo=MOCK_VIM_INFO)
 
-        self.assertIsNone(resp)
+        self.assertEquals(retcode, 11)